#include <iostream>
using namespace std;
bool isLeapYear(int year) {
    if (year % 4 != 0) {
        return false;
    } else if (year % 100 != 0) {
        return true;
    } else if (year % 400 == 0) {
        return true;
    } else {
        return false;
    }
}
int main() {
    int a, b;
    cin >> a >> b;
    
    int count = 0;
    for (int year = a; year <= b; year++) {
        if (isLeapYear(year)) {
            count++;
        }
    }
    
    cout << count << endl;
    return 0;
}  
									
									
									
									
								
#include 
using namespace std;
bool isLeapYear(int year) {
    if (year % 4 != 0) {
        return false;
    } else if (year % 100 != 0) {
        return true;
    } else if (year % 400 == 0) {
        return true;
    } else {
        return false;
    }
}
int main() {
    int a, b;
    cin >> a >> b;
    
    int count = 0;
    for (int year = a; year <= b; year++) {
        if (isLeapYear(year)) {
            count++;
        }
    }
    
    cout << count << endl;
    return 0;
}
So easy La don't need to post