View Compilation Error

0_0_15503938_8106.cpp: In function 'void dfs(int, int)':
0_0_15503938_8106.cpp:24:9: error: 'x' was not declared in this scope
  if(res[x][y]!=0)return;
         ^
0_0_15503938_8106.cpp:24:12: error: 'y' was not declared in this scope
  if(res[x][y]!=0)return;
            ^