#include<bits/stdc++.h>
using namespace std;
int main(){
	int a,h;
	cin>>a;
	if(a>=90){
		h=a*3;
		cout<<h;
	}
	if(90>a>=80){
		h=a*2;
		cout<<h;
	}
	if(70>a){
		h=50;
		cout<<h;
}
	if(80>a>=70){
		h=a;
		cout<<h;
	}
}
/**************************************************************
	Problem: 1300
	User: tonghuawei
	Language: C++
	Result: Wrong Answer
****************************************************************/