C :

#include <stdio.h>
 int main ()
 {
 	int n,m;
 	scanf("%d",&n);
 	m=3*n;
 	printf("%d",m);
 	return 0;
 }

C++ :

#include<iostream>
using namespace std;
int main(){
	int n;
	cin>>n;
	cout<<n*3;
} 

Java :

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc = new Scanner (System.in);
		int a = sc.nextInt();
		System.out.print(qingWa(a));
		
	}
	public static int qingWa(int a) {
		int n = 0;
		for (int i=1;i<=a;i++) {
			n=n+3;
		}
		return n;
	
	}

}

Python :

s = input()
print(int(s)*3)