C :

#include<stdio.h>
#include<math.h>
int main()
{
	int n,i,j;
	scanf("%d",&n);
	for(i=1;i<=n;i++)
	{
		for(j=1;j<=n;j++)
		{
			printf("*");
		}	printf("\n");
	}
}
	

C++ :

#include <iostream>
using namespace std;

int main(){
	int i,j,n;
	cin>>n;
	for(i = 1;i <= n;i++){
		for(j = 1;j <= n;j++){
			cout<<"*";
		} 
		cout<<endl;
	}
	return 0;
}

Pascal :

program ex_1;
var
  i,j,m:longint;
begin
  read(m);
  for i:=1 to m do begin
    for j:=1 to m do write('*');
    writeln;end;
end.

Java :

import java.util.Scanner;
public class Main{
	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		int n=scanner.nextInt();
		for(int i=1;i<=n;i++){
			for(int j=1;j<=n;j++){
				System.out.print("*");
			}
			System.out.println();
		}
	}
}

Python :

n = int(input())
for i in range(1,n+1):
    for j in range(1,n+1):
        print('*',end='')
    print()