取log比较大小

//#include <bits/stdc++.h>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <string>
#include <stdio.h>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <string.h>
#include <vector>
#define ME(x , y) memset(x , y , sizeof(x))
#define SF(n) scanf("%d" , &n)
#define rep(i , n) for(int i = 0 ; i < n ; i ++)
#define INF  0x3f3f3f3f
#define mod 20191117
#define PI acos(-1)
using namespace std;
typedef long long ll ;

int main()
{
    int n ;
    while(~scanf("%d" , &n) && n)
    {
        double w = 2 ;
        for(int i = 1960 ; i <= n ; i+=10)
        {
            w *= 2 ;
        }
        w *= log(2);
        int ans = 1 ;
        double f=0 ;
        while(w >= f)
        {
            f += log((double)++ans);
        }
        cout << ans - 1 << endl ;
    }
    return 0;
}