#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; bool s(int i){ if(i%100==0){ if(i%400==0){ z++; } } else if(i%4==0){ z++; } } int main(){ int x,y,z=0; cin>>x>>y; for(int i=x;i<=y;i++){ s(i); } cout<<z<<endl; return 0; }