C :: Program To Find Mean Of Elements In Columns Which Are Divided By 3

The program need to find mean of elements in columns which are divided by 3. And to print which colmn has the greater mean

Example

For matrix:
7 9 5
17 15 30
29 34 60

Program print: 0 12 45. The greater mean: 3 column.

I wrote this code and it prints 0 12 45 idk how to find which column has greater mean?

Code:

#include <stdio.h>
#define max 50
int main()
{int n,m,i,j,k,d,br=0,suma;
int a[max][max];
int b[max][max];
printf("Kolku redici i kolku koloni da imat matricite: ");
scanf("%d %d ", &n,&m);

[Code]...