A

#include <bits/stdc++.h>

#define fr ifrst
#define sc second
#define pb push_back
#define mk make_pair
#define sz(s) s.size()
#define all(s) s.begin(),s.end()
#define ll long long

using namespace std;

const int N = 1e5 + 7;
const int inf = 1e9 + 7;

int n, a, b;

main() {
    cin >> n >> a >> b;
    ll ans = 0;
    while (a || b){
        int t1 = 0, t2 = 0;
        if (b){
            t1 = min(b, n);
        }
        if (a){
            t2 = min(a, n - t1);
        }
        a -= t2;
        a += t1;
        b -= t1;
        ans += 20;
    }
    ans -= 10;
    cout << ans;
}