#include <iostream> #include <cstdio> using namespace std; bool a(int e){ if(e%100!=0&&e%4==0||e%400==0) return true; return false;} int main() { int x,y,z=0; cin>>x>>y; for(int i=x;i<=y;i++){ if(a(i)) z++;}cout<<z; return 0; }