#include <bits/stdc++.h>
using namespace std;
int main() {
    int n, m;
    cin >> n >> m;
    int cnt = 0;
    for (int i = n; i <= m; i++) {
        int x = i;
        bool flag = false;
        while (x) {
            int a = x % 10;
            if (a % 2 == 0) flag = true;
            x /= 10;
        }
        if (!flag) cnt++;
    }
    cout << cnt << endl;

    return 0;
}