#include<iostream> #include<cstdio> using namespace std; int main(){ int n,m; int sum=0; cin>>n>>m; for(int i=n;i<=m;i++){ int t=i; while(t>0){ int g=t%10; int sg=t%100; if(g==4||sg==62){ sum++; break; } t=t/10; } } cout<<m-n+1-sum; return 0; }