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