#include<bits/stdc++.h> using namespace std; bool run(int year){ if(year%4==0&&year%100!=0){ return 1; } else if(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(run(i)==1){ sum++; } } cout<<sum; return 0; }