#include<bits/stdc++.h>
using namespace std;
double a[20][20],d,det;
int n;
int prim(int a) {
    if(a < 2)
    	return 0;
    for(int i = 2; i * i <= a; i++)
    	if(a % i == 0)
    		return 0;
    return 1;
    }

int prime = 0;
int main(){
	ifstream cin("prob.in");
	ofstream cout ("prob.out");
	cin>>n;
	for(int i=1;i<=n;i++)
	    for(int j=1;j<=n;j++)
	        cin>>a[i][j];
	for(int i=1;i<=n;i++){
		for(int j=i+1;j<=n;j++)
		    if(j!=i){
		        d=a[j][i]/a[i][i];
				for(int k=1;k<=n;k++)
				    a[j][k]-=a[i][k]*d;
			}
	}
	cout<<endl<<"matricea zerografiata "<<endl;
	for(int i=1;i<=n;i++){
	    for(int j=1;j<=n;j++)
	        cout<<setprecision(2)<<fixed<<a[i][j]<<' ';
	    cout<<endl;
    }det=1;
    for(int i=1;i<=n;i++){
        det*=a[i][i];
        if(prim(abs(a[i][i]))){
            prime++;
        }
        }
    cout<<"Determinantul ="<<det<<endl;
    if(prime > 1)cout << "avem "<<prime << " nr prime pe diagonala" <<endl;
    if(prime = 1)cout << "avem un numar prim pe diagonala"<<endl;
    if(!prime) cout << "nu sunt numere prime pe diagonala " <<endl;
	return 0;
}