# include<iostream> using namespace std; int a(int n){ if(n%100==0){ if(n%400==0)return 0; else return 1; } else { if(n%4==0)return 0; else return 1; } } int main(){ int x,y,l=0; cin>>x>>y; for(int i=x;i<=y;i++){ if(a(i)==0)l++; } cout<<l<<endl; return 0; }