#include <bits/stdc++.h>
using namespace std;
int main(){
	int n,t;
	cin>>n;
	if(a>=90)t=n*3;
	else if(a>=80)t=n*2;
		else if(a>=70)t=n;
			else cout<<"50";
	cout<<t;
	return 0;
	}

/**************************************************************
	Problem: 1300
	User: ljl2
	Language: C++
	Result: Compile Error
****************************************************************/