/in/foo.cc:16:7: error: unable to find numeric literal operator 'operator""o1'
 int r[10o1][10o1],f[101],n,m,cnt;
       ^~~~
/in/foo.cc:16:7: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes
/in/foo.cc:16:13: error: unable to find numeric literal operator 'operator""o1'
 int r[10o1][10o1],f[101],n,m,cnt;
             ^~~~
/in/foo.cc:16:13: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes
/in/foo.cc: In function 'void change(int, int)':
/in/foo.cc:19:2: error: 'r' was not declared in this scope
  r[i][j]^=1;
  ^
/in/foo.cc: In function 'bool check()':
/in/foo.cc:30:8: error: 'r' was not declared in this scope
    if(!r[i][j]) return 0;
        ^
/in/foo.cc: In function 'void dfs(int)':
/in/foo.cc:55:7: error: 'r' was not declared in this scope
   if(!r[now-1][i])
       ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:68:10: error: 'r' was not declared in this scope
   memset(r,0,sizeof r);
          ^