#include<bits/stdc++.h> using namespace std; bool o(int year){ if(year%4==0&&year%100!=0||year%400==0){ return true; } return false; } int main(){ int x,y,cnt=0; cin>>x>>y; for(int i=x;i<=y;i++){ if(o(i)){ cnt++; } } cout<<cnt; return 0; }