#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 run(int a){ int rum_s=0; if(a%4==0 && a%100>0) rum_s++; else if(a%400==0) rum_s++; return rum_s; } int main(){ int s=0,x,y; cin>>x>>y; for(int i=x;i<=y;i++){ s+=run(i); } cout<<s; return 0; }