View Compilation Error

0_0_36241147_30766.cpp: In function 'int main()':
0_0_36241147_30766.cpp:22:29: error: 'N' was not declared in this scope
         for (int i = 0; i < N; i ++)
                             ^
0_0_36241147_30766.cpp:24:13: error: 'f' was not declared in this scope
             f[i][j] = 0;
             ^