// Giải thuật dig cho bài toán dig-num-square\n#include <bits/stdc++.h>
using namespace std;
using ll = long long;

const int MAX_SUM_SQ = 9 * 9 * 18 + 5;
bool isPrime[MAX_SUM_SQ];

void sieve() {
    fill(isPrime, isPrime + MAX_SUM_SQ, true);
    isPrime[0] = isPrime[1] = false;
    for (int i = 2; i * i < MAX_SUM_SQ; i++) {
        if (isPrime[i]) {
            for (int j = i * i; j < MAX_SUM_SQ; j += i)
                isPrime[j] = false;
        }
    }
}

string s;
int n;
ll dp[20][2][1500];

ll solve(int pos, bool tight, int sumSq) {
    if (pos == n) return isPrime[sumSq] ? 1 : 0;
    // Kiem tra xem tong binh phuong co phai nguyen to khong

    ll &res = dp[pos][tight][sumSq];
    if (res != -1 && !tight) return res;

    int limit = tight ? (s[pos] - '0') : 9;
    ll ans = 0;
    for (int d = 0; d <= limit; d++) {
        bool ntight = tight && (d == limit);
        ans += solve(pos + 1, ntight, sumSq + d * d);
    }
    if (!tight) res = ans;
    return ans;
}

ll countUpTo(ll N) {
    if (N < 0) return 0;
    s = to_string(N);
    n = s.size();
    memset(dp, -1, sizeof(dp));
    return solve(0, true, 0);
}

int main() {
    // Doc du lieu dau vao
    sieve();
    ll L, R;
    cin >> L >> R;
    cout << countUpTo(R) - countUpTo(L - 1) << '\n';
    return 0;
}