#include<iostream> using namespace std; int main(){ int n,m; int a,b,c,d=0; cin>n>>m; for(int i=n;i<=m;i++) a = i; while(a!=0){ b = a%10; d = a%100; if(b==4||d==62){ c++; break } a= a/10; } cout<<m-n+1-c; return 0; }