#include <iostream> #include <cstdio> using namespace std; int a(int l){ int o=l,p; if(o%400==0 && o%100==0 || o%4==0 ) p=1; else p=0; return p; } int main(){ int n,b,m=0,i; cin>>n>>b; for (i=n;i<=b;i++) m+=a(i); cout<<m; return 0; }