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