Sum of diognal metrix

#include <iostream>
using namespace std;
const int MAX = 100;

void Diagnol_Sum(int add[][MAX], int n){
    int principal = 0, secondry = 0;
    for(int i=0; i<n; i++){
        for( int j=0; j<n; j++){
            if(i == j){
                principal += add[i][j];
            }
            if((i+j) == (n-1)){
                secondry += add[i][j];
            }
        }
    }
    cout<<"print principal sum : "<<principal<<endl;
    cout<<"print Secondry sum : "<<secondry<<endl;
}

int main(){
    int a[][MAX] = {{1,2,3,4},
                    {1,4,7,8},
                    {3,5,6,8},
                    {7,5,9,2}};
                
    Diagnol_Sum(a, 4);
    return 0;
}