#pragma GCC optimize ("O3")

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
#define int ll
typedef tree<
        pair<int, int>,
        null_type,
        less<pair<int, int>>,
        rb_tree_tag,
        tree_order_statistics_node_update>
        ordered_set;//order_of_key()->gives how many elements less than specific element in the set ,, find_by_order() ->find specific element by index the set
#define  ll long long
#define  el '\n'
#define IO       \
    ios_base::sync_with_stdio(0); \
    cin.tie(0);                   \
    cout.tie(0);

#define endl '\n'
using namespace std;
int const N  =  2e6 +5  ;

void pre() {
    vector<int> v(N, false);
    for (int i = 2; i <= N; i++) {
        for (int j = 2 * i; j <= N and !v[i]; j += i) {
            v[j] = 1;
        }
    }
    int cnt = 0;
    vector<string> all;
    for (int i = 2; i <= N; i++) {
        if (!v[i]) {
            string s = to_string(i);
            all.push_back(s);
        }
    }
    int l, r;
    cin >> l >> r;
    string p;
    cin >> p;
    l--, r--;
    cnt = 0;
    for (int i = l; i <= r; i++) {
        bool can = 0;
        if (all[i].size() >= p.size()) {
            for (int j = 0; j < all[i].size() - p.size() + 1; j++) {
                if (all[i].substr(j, p.size()) == p) {
                    can = 1;
                }
            }
            cnt += can;
        }
    }
    cout << cnt << endl;
}

/*void test() {
    vector<int> tmp = {1,2,3,5};
     auto i = lower_bound(tmp.begin() + 1, tmp.end(),4);
     cout << *i << el;
}*/
signed main() {
    pre() ;
    IO

}