View Compilation Error

0_0_20642762_17283.cpp: In function 'bool checkxy(int, int)':
0_0_20642762_17283.cpp:33:8: error: 'nn' was not declared in this scope
     if(nn.x < 0 || nn.y < 0 || nn.x >= M || nn.y >= N || v[nn.x][nn.y] == 1 || a[nn.x][nn.y] == '*') return false;
        ^