#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; int a(int a,int b){ int sum=0; for(int i=a;i<=b;i++){ if(i%4==0&&i%100!=0||i%400==0){ sum++; } } return sum; } int main(){ int x,y; cin>>x>>y; cout<<a(x,y)<<endl; return 0; }