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

int main() {
    double n;
    cin>>n;
    if (n==1) cout<<1*5000;
    //meothinhle
    else if (n>1 && n<=30) cout<<(n-1)*4000+1*5000;
    else cout<<1*5000+29*4000+(n-30)*3000;
    return 0;
}