#include<stdio.h>
int main(){
 int a[10][10],i,j,sum=0,m,n;
 printf("\nEnter the row and column of matrix: ");
scanf("%d %d",&m,&n);
 printf("\nEnter the elements of matrix: ");
 for(i=0;i<m;i++)
 for(j=0;j<n;j++)
 scanf("%d",&a[i][j]);
printf("\nThe matrix is\n");
 for(i=0;i<m;i++){
 printf("\n");
 for(j=0;j<m;j++){
 printf("%d\t",a[i][j]);
 }
}
for(i=0;i<m;i++){
 for(j=0;j<n;j++){
 if(i==j)
 sum=sum+a[i][j];
 }
}
printf("\n\nSum of the diagonal elements of a matrix is: %d",sum);
return 0;
}