/** libraries */
#include <iostream>
#include <cmath>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <algorithm>
/** libraries */
using namespace std;
/** defines */
#define ll long long
#define ld long double
#define yes cout << "YES" << "\n"
#define no cout << "NO" << "\n"
/** defines */
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
ld a;
cin >> a;
if(a > 0)
a += 20;
cout << a;
}
