79a7fc66.cpp

constexpr int DIGIT = 20;

int a[DIGIT];
int dp[DIGIT][2];

int dfs(int pos, int pre, bool status, bool limit)
{
    if (pos == -1)
    {
        return 1;
    }

    if (!limit && dp[pos][status] != -1)
    {
        return dp[pos][status];
    }

    int _cac = limit ? a[pos] : 9;
    int res = 0;

    for (int i = 0; i <= _cac; i++)
    {
        if ((pre != 6 || i != 2) && i != 4)
        {
            res += dfs(pos - 1, i, i == 6, limit && i == a[pos]);
        }
    }

    if (!limit)
    {
        dp[pos][status] = res;
    }

    return res;
}

inline int solve(int x)
{
    int pos = 0;
    while (x)
    {
        a[pos++] = x % 10;
        x /= 10;
    }
    return dfs(pos - 1, -1, 0, 1);
}

int l, r;

int main()
{
    while (~scanf("%d %d", &l, &r) && (l != 0 || r != 0))
    {
        memset(dp, -1, sizeof(dp));
        printf("%d\n", solve(r) - solve(l - 1));
    }
}