#include <bits/stdc++.h>
using namespace std;
typedef long long LL;

bool check(int n){
    return n % 4 == 0 && n % 100 != 0 || n % 400 == 0;
}

void fun(int s, int e){
    int sum = 0;
    for (int i = s; i < e; i++)
        if (check(i)) sum ++;
    printf("%d", sum);
}

int main()
{
  int start_year = 2000, end_year = 2400;
  fun(start_year, end_year);
  return 0;
}