#include<iostream>
#include<algorithm>
using namespace std;
int a[12]={31,28,31,30,31,30,31,31,30,31,30,31};
void rn(int i)
{
    if (i%4==0&&i%100!=0||i%400==0)
        a[1] = 29;
    else
        a[1] = 28;
}
int main()
{
    int n,i,j,k,s=4,d=1,m=4,cnt=0;
    cin>>n;
    for (i=1998; i<=n; i++)
    {
        rn(i);  
        k=0;
        while (1)
        {
            d++;    
            m=(m+1)%7;  
            if (d==13 && m==5 && i==n)/
            {
                cnt++;
            }
            if (d==a[k])
            {
                d=0;
                k++;
                if (k>=12)
                {
                    break;
                }
            }
        }
    }
    cout<<cnt;
    return 0;
}
/**************************************************************
	Problem: 1853
	User: wangyiyang
	Language: C++
	Result: Compile Error
****************************************************************/