QwQ

#include<bits/stdc++.h>
using namespace std;

int main () {
	int n, sum;
	cin >> n;
	for ( int i = 100; i <= 1000; i += 50 ) {
		if ( n <= i ) {
			sum = i;
			break;
		}
	}
	cout << sum;
	return 0;
}