# Poj Solution 3188

```http://poj.org/problem?id=3188

#include <stdio.h>
#include <algorithm>

using namespace std;

char w[1000][11];

int button[26];

__int64 a[1000];
int n, B, L;
int flag[26];

void clac( int &s1, int &s2 ) {
int i, j;
s1 = 0, s2 = 0;
flag[B] = 100;
for( i=0, j=0; i<L; i++ ) {
if( i == flag[j] )
j++;
button[i] = j+1;
}

__int64 t;
for( i=0; i<n; i++ ) {
t = 0;
for( j=0; w[i][j]; j++ )
t = ((t<<5) | button[ w[i][j] - 'A' ]);
a[i] = t;
}

sort( a, a+n );

for( i=0; i<n; i=j ) {
for( j=i+1; j<n && a[i] == a[j]; j++ )
;
s1++;
s2 += (j==i+1);
}

return ;
}

int ans;
int best[27];

void search( int k, int ch ) {
if( ans == n )
return;
if( k == B-1 ) {
int s1, s2;
clac( s1, s2 );
if( s2 > ans ) {
ans = s2;
for( int i=0; i<L; i++ )
best[i] = button[i];
}
return;
}

int i;

for( i=L-(B-k); i>=ch; i-- ) {
flag[k] = i+1;
search( k+1, i+1 );
}
}

int main( ) {
int i;
scanf( "%d%d%d", &B, &L, &n );

for( i=0; i<n; i++ )
scanf( "%s", w+i );

ans = 0;
search( 0, 0 );

printf( "%dn", ans );
for( i=0; i<L; i++ ) {
printf( "%c", 'A'+i );
if( best[i] != best[i+1] )
printf( "n" );
}

return 0;
}

```
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