#include <iostream> #include <cstdio> #include <iomanip> #include <cmath> using namespace std; int main () { int n; double m=0; cin >> n; if (n<=150) { m = n*0.4463; } else if (n>=150 && n<=400) { m = 150*0.4463+(n-150)*0.4663; } else { m = 150*0.4463+(400-150+1)*0.4663+(n-400)*0.5663; } printf("%.1f",m); return 0; }