28ma matrici

#include <stdio.h>

int main ()
{
    int i,j,m,n,a[100][100],suma=0;
    scanf ("%d %d",&m,&n);
    for (i=0;i<m;i++)
    {
        for (j=0;j<n;j++)
        {
            scanf ("%d",&a[i][j]);
        }
    }

    for (i=0;i<m;i++)
    {
        for (j=0;j<n;j++)
        {
            if (i%2==0 && j%2!=0)
            {
                suma = suma + a[i][j];
            }
            if (j%2==0 && i%2!=0)
            {
                suma = suma + a[i][j];
            }
        }
    }

    for (i=0;i<m;i++)
    {
        printf("\n");
        for (j=0;j<n;j++)
        {
            if (i==j)
            {
                printf (" %d",suma);
            }
            else
            {
                printf (" %d",a[i][j]);
            }
        }
    }


    return 0;
}