View Compilation Error

0_0_32317456_9820.cpp: In function 'void dfs(int, int)':
0_0_32317456_9820.cpp:19:7: error: 'xxx' was not declared in this scope
     r[xxx][yyy]='@';
       ^
0_0_32317456_9820.cpp:19:12: error: 'yyy' was not declared in this scope
     r[xxx][yyy]='@';
            ^