hd 1141

 1 #include <iostream>
 2 #include <cmath>
 3 using namespace std;
 4 double const pi=3.1415926;
 5 double const e=2.718281828459;
 6 
 7 int main()
 8 {
 9     int y;
10     while(cin>>y&&y)
11     {
12         int bit=pow(2,(y-1960)/10+2);
13         int n=2;
14         while(n++)
15         {
16             double t=0.5*log2(2*pi*n)+n*log2(n/e);
17             if(t>bit) break;
18         }
19         cout<<--n<<endl;
20     }
21     return 0;
22 }