foo.cc:3:9: error: redefinition of ‘int m’
    3 | int m,n,m,a[1001][1001],cnt;
      |         ^
foo.cc:3:5: note: ‘int m’ previously declared here
    3 | int m,n,m,a[1001][1001],cnt;
      |     ^
foo.cc: In function ‘int main()’:
foo.cc:5:20: error: ‘k’ was not declared in this scope
    5 |         cin>>m>>n>>k;
      |                    ^