#include<bits/stdc++.h>
#define ll int
#define el '\n'
#define all(a) a.begin(),a.end()

#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
template<typename T>

using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const ll N=1299709+200,mod=1e9+7;
string str;
ll counter = 0;
ll ans = 0;
ll l , r;

bool arr[N+100];

bool is_sub(string s1)
{
    if (str.size() > s1.size()) return true;
    if (s1.find(str) != string::npos)
    {
        return false;
    }
    return true;
}
void sieve()
{
    for (ll i = 2 ; i <= N ; i ++)
    {
        if (!arr[i])
        {

            counter++;
            if (l <= counter && counter <= r)
            {
//                cout << i << el;
                if (!is_sub(to_string(i))){ans++;}
            }
            if (counter == r)
            {
                return;
            }
            for (ll j = i + i ; j <= N ; j += i )
            {
                arr[j] = true;
            }
        }
    }

}

void solve(ll t) {


    cin >> l >> r;
    cin >> str;
    sieve();
    cout << ans;

}
signed main() {
    ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);

    ll t;
    //cin >> t;
    t = 1;
    for (ll i = 0 ; i < t ; i ++)
    {
        solve(i);
    }
}