1111

#include <iostream>
using namespace std;

int main() {
	int years1;
	int years2;
	int count1 = 0;
	cin >> years1 >> years2;
	for (int i = years1; i <= years2; i++) {
		if ((i % 4 == 0 && i % 100 != 0) || (i % 400 == 0)) {
			++count1;
		}
	}
	cout << count1;
	return 0;
}