#include <iostream>
#include <cmath>
#include <iomanip>
#include <random>
#include <algorithm>
#include <math.h>
#include <string>
#include <sstream>

using namespace std;
int isPalindrom(int a);

int count(int a, int b) {
    int count = 0;
    bool prime;
    for (int i = a; i <= b; i++) {
        prime = true;
        double sqrti = sqrt((double)i);
        for (int j = 2; j < sqrti + 1; j++)
            if (i % j == 0) {
                prime = false;
                break;
            }
        if (prime)
            count++;
        count += isPalindrom(i);
    }

    return count;
}
int isPalindrom(int a) {
    int  b;
    stringstream ss;

    b = a;
    while (b > 0)
    {
        ss << b % 10;
        b /= 10;
    }
    ss >> b;
    if (a == b)
        return 1;
    else
        return 0;
}
int getReverse(int n) {
    int r = n % 10;
    while (n /= 10) {
        r = r * 10 + n % 10;
    }
    return r;
}
int main() {
    int a = 0, b = 0;
    cin >> a >> b;
    cout << "count = " << count(a, b);

    return 0;
}