/in/foo.cc: In function 'int main()':
/in/foo.cc:6:12: warning: left operand of comma operator has no effect [-Wunused-value]
    6 |         if(m,n,p<2||m,n,p>=100)
      |            ^
/in/foo.cc:6:21: warning: right operand of comma operator has no effect [-Wunused-value]
    6 |         if(m,n,p<2||m,n,p>=100)
      |                     ^
/in/foo.cc:6:19: warning: right operand of comma operator has no effect [-Wunused-value]
    6 |         if(m,n,p<2||m,n,p>=100)
      |                ~~~^~~
/in/foo.cc:6:28: warning: right operand of comma operator has no effect [-Wunused-value]
    6 |         if(m,n,p<2||m,n,p>=100)
      |                            ^~~
/in/foo.cc:9:13: error: declaration of 'c' as multidimensional array must have bounds for all dimensions except the first
    9 |         int c[][];
      |             ^
/in/foo.cc:13:17: error: 'c' was not declared in this scope
   13 |                 c[i][j] += a[i][k]*b[k][j];
      |                 ^
/in/foo.cc:19:21: error: 'C' was not declared in this scope
   19 |             cout << C[i][j];
      |                     ^