#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <map>

using namespace std;




int main(){
    long long n,daym[7]={0},day=0,ans;
    
    scanf("%lld",&n);
    
    for(int i=1;i<=400;i++){
        if((i%4==0 && i%100!=0) || i%400==0)
            day=(day+2)%7;
        else
            day=(day+1)%7;
        
        daym[day]++;
    }
    
    ans=(n-2000)/400*daym[3];
    
    day=0;
    for(int i=1;i<=(n-2000)%400;i++){
        if((i%4==0 && i%100!=0) || i%400==0)
            day=(day+2)%7;
        else
            day=(day+1)%7;
        
        if(day==3)
            ans++;
    }
    
    printf("%d\n",ans-3);
    return 0;
}