// I AM A MUSLIM

#include "bits/stdc++.h"

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")

#define fast_io std::ios::sync_with_stdio(0);std::cin.tie(0)
#define lli long long int
#define flush fflush(stdout)
#define line printf("\n")
#define yn(a, b) printf("%s\n", (a) >= (b) ? "Yes":"No")
#define amodm(a, M) (((a)%M+M)%M)
// #define int lli

using pii = std::pair<int,int>;

const int MOD = 1000000007;
const int mxN = 500100;

signed main() {
    int testCases=1;
    // scanf("%d",&testCases);
    
    for (int TC = 1; TC <= testCases; TC++) {
        int n;
        scanf("%d",&n);
        
        int fi = n/500;
        int ans = fi*1000;
        n -= fi*500;
        ans += n/5*5;
        printf("%d\n", ans);
        
    }
    
    return 0;
}