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