题意：。。

水题

代码：

#include <stdio.h>
#include <string.h>
#include <algorithm>
using namespace std;
int s[10];
int ans[1000005] = {0, 1};
int is(int n){
    //n = 62;
    int pre = 0, cur = 0, i;
    while(n){
        pre = cur;
        cur = n%10;
        n /= 10;
        if(cur == 4||(cur == 6&&pre == 2)) return 1;
    }
    return 0;
}
int f()
{
    int i;
    for(i = 1; i < 1000005; i ++){
        if(is(i)){
            ans[i] = ans[i-1];
        }
        else ans[i] = ans[i-1]+1;
    }
}
int main()
{
    int n, m;
    f();
    while(scanf("%d%d", &n, &m), n, m){
        printf("%d\n", ans[m]-ans[n-1]);
    }
    return 0;
}