#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;
typedef unsigned long long ull;
typedef double db;
typedef long double ldb;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
#define f first
#define s second
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define IO ios_base::sync_with_stdio(0), cin.tie(0)
const int mod = 1e9 + 7;
template <typename T>
void readArray(vector<T> &A)
{
    for (T &i : A)
        cin >> i;
}
template <typename T>
void readArray(vector<vector<T>> &A)
{
    for (vector<T> &i : A)
        readArray(i);
}
template <typename T>
void printArray(vector<T> A)
{
    for (T i : A)
        cout << i << " ";
    cout << endl;
}
ll fastPow(ll a, ll b, ll m = mod)
{
    a %= m;
    ll res = 1;
    while (b > 0)
    {
        if (b & 1)
            res = res * a % m;
        a = a * a % m;
        b >>= 1;
    }
    return res;
}
bool isPrime(ll n, int iter = 5)
{
    if (n < 4)
        return n == 2 || n == 3;
    for (int i = 0; i < iter; i++)
    {
        int a = 2 + rand() % (n - 3);
        if (fastPow(a, n - 1, n) != 1)
            return false;
    }
    return true;
}
ll inv(ll n, ll m = mod)
{
    return fastPow(n, m - 2);
}
ll mul(ll a, ll b, ll m = mod)
{
    return (a * b) % m;
}
ll add(ll a, ll b, ll m = mod)
{
    return (a + b + m) % m;
}
void solve()
{
    int l, h;
    string p;
    cin >> l >> h >> p;
    vector<string> primes;
    int mxn = 2e6;
    vector<int> sp(mxn, -1);
    for (int i = 2; i < mxn; i++)
    {
        if (sp[i] == -1)
        {
            primes.push_back(to_string(i));
            for (int j = 1; j * i <= mxn; j++)
            {
                if (sp[j * i] == -1)
                    sp[j * i] = i;
            }
        }
    }
    int cnt = 0;
    for (int z = l - 1; z < h; z++)
    {
        string i = primes[z];
        for (int j = 0; j <= (int)i.length() - (int)p.length(); j++)
        {
            bool ok = true;
            for (int k = 0; k < (int)p.length(); k++)
            {
                if (i[j + k] != p[k])
                {
                    ok = false;
                    break;
                }
            }
            if (ok)
            {
                cnt++;
                // cout << z << " " << i << "\n";
                break;
            }
        }
    }
    cout << cnt;
}
void trials()
{
    int t, tt;
    for (cin >> t, tt = t; t--; cout << endl)
    {
        // cout << "Case #" << tt - t << ": ";
        solve();
    }
}
int main()
{
    // freopen("","r",stdin);
    IO;
    solve();
}