View Compilation Error

0_0_18216320_26648.cpp: In function 'bool dfs(int, int)':
0_0_18216320_26648.cpp:21:10: error: 'nx' was not declared in this scope
     mvis[nx][ny] = true;
          ^
0_0_18216320_26648.cpp:21:14: error: 'ny' was not declared in this scope
     mvis[nx][ny] = true;
              ^