//#define HOME
#include <bits/stdc++.h>
#ifndef HOME
#include "memory.h"
#include "grader.h"
#endif // HOME
#ifdef HOME
static char card[51];
static int up[2], is_up[51], candy[25], candies, moves;
char faceup(int C){
int c0, c1;
if (C < 1 || C > 50 || is_up[C]) {
exit(92);
}
is_up[C] = 1;
up[moves%2] = C;
moves++;
if (moves%2 == 0) {
c0 = card[ up[0] ] - 'A';
c1 = card[ up[1] ] - 'A';
if (c0==c1 && !candy[c0]) {
candy[c0] = 1;
++candies;
}
is_up[ up[0] ] = is_up[ up[1] ] = 0;
}
return card[C];
}
#endif // HOME
const int MAX_N = 50;
int cached_card[1 + MAX_N];
std::vector <int> pos[1 + MAX_N];
#define pb push_back
void play() {
for (int i = 0; i <= MAX_N; i++)
pos[i].clear (), cached_card[i] = 0;
for (int i = 1; i <= MAX_N; i += 2) {
cached_card[i] = faceup (i) - 'A';
cached_card[i + 1] = faceup (i + 1) - 'A';
if (cached_card[i] != cached_card[i + 1]) {
pos[cached_card[i]].pb (i);
pos[cached_card[i + 1]].pb (i + 1);
}
}
for (int i = 0; i <= MAX_N; i++)
if (pos[i].size () == 2) {
faceup (pos[i][0]);
faceup (pos[i][1]);
}
}
#ifdef HOME
void playgame(){
int i;
for (i=1;i<=50;i++) {
// card[i] = getchar();
card[i] = rand () % 25 + 'A';
}
moves = candies = 0;
play();
if (candies != 25) {
exit(91);
}
}
int main(){
playgame();
printf("OK %d\n",moves);
return 0;
}
#endif // HOME
