one.java

import java.util.*;

class Solution {
    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        
        int result = 0;
        
        if(n % 2 == 0) {
            for(int i=0;i<(n/2)-1;i++){
                result += 275;
            }
        }
                
        if(n % 2 != 0){
            for(int i=0;i<(n/2);i++){
                result += 550;
            }
        }
        
        System.out.println(result);
    }
}