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