func_code_string: #include <bits/stdc++.h>   using namespace std;   const int INF = 1e9;   const int MN = 105;   bool mark[500][500];   char s[MN];   int dis[500][500];   int ask(pair<int, int> now) {     int res = INF;     if (mark[now.first][now.second]) res = min(res, dis[now.first][now.second]);     if (mark[now.first - 1][now.second])       res = min(res, dis[now.first - 1][now.second] + 1);     if (mark[now.first + 1][now.second])       res = min(res, dis[now.first + 1][now.second] + 1);     if (mark[now.first][now.second - 1])       res = min(res, dis[now.first][now.second - 1] + 1);     if (mark[now.first][now.second + 1])       res = min(res, dis[now.first][now.second + 1] + 1);     return res;   }   int main() {     scanf( %s , s);     int l = strlen(s);     pair<int, int> now = make_pair(105, 105);     mark[105][105] = 1;     dis[105][105] = 0;     int len = 0;     for (int i = 0; i < l; ++i) {       ++len;       if (s[i] ==  U ) now.second += 1;       if (s[i] ==  D ) now.second -= 1;       if (s[i] ==  L ) now.first -= 1;       if (s[i] ==  R ) now.first += 1;       if (ask(now) < len) {         printf( BUG n );         return 0;       }       mark[now.first][now.second] = 1;       dis[now.first][now.second] = len;     }     printf( OK n );     return 0;   }   