#include<bits/stdc++.h>
using namespace std;
int main(){
	int n;
	cin>>n;
	if(n>=90){
		cout<<n*3;
	if(n>=80&&n<90){
     	cout<<n*2;
     	if(n>=70&&n<80){
     		cout<<n;
     		if(n<70){
     			cout<<"50";
			 }
		 }
	}	
}
	return 0;
} 
/**************************************************************
	Problem: 1300
	User: houlingqi2
	Language: C++
	Result: Wrong Answer
****************************************************************/