#include #define ll long long #define ull unsigned long long #define mod 1e9 #define vll vector #define pb push_back #define what_is(x) cerr << #x << " is " << x << endl; using namespace std; inline void sol() {} double exp(double a, long b){ double ans = 1; while(b != 0){ if(b%2) ans = ans*a; a = a*a; b = b / 2; } return ans; } int main() { ios_base::sync_with_stdio(false); cin.tie(0); double x; cin>>x; if(x >= 20){ cout<<0<