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