#include<bits/stdc++.h> using namespace std; bool a(int year){ if(year%4==0&&year%100!=0||year%400==0) return 1; else return 0; } int main() { int x,y,sum=0; cin>>x>>y; for(int i=x;i<=y;i++){ if(a(i)) sum++; } cout<<sum; return 0; }