#include <bits/stdc++.h>
#define endl '\n'
#define ll long long
#define fast                 \
    ios::sync_with_stdio(0); \
    cin.tie(0);              \
    cout.tie(0);
using namespace std;
const int N = 1e7 + 10;
bool si[N];
bool contains(int num, string x)
{
    string temp;
    while(num>0)
    {
        temp.push_back((num%10) + '0');
        num /= 10;
    }
    reverse(temp.begin(),temp.end());
    if(x.size()>temp.size()) return 0;
    for(int i=0;i<=temp.size()-x.size();i++)
    {
        bool ok = 1;
        for(int j=0;j<x.size();j++)
        {
            ok &= temp[i+j]==x[j];
        }
        if(ok)
        {
            return 1;
        }
    }
    return 0;
}
void solve()
{
    vector<int> primes;
    for (int i = 2; i < N; i++)
    {
        if (si[i])
            continue;
        primes.push_back(i);
        if (primes.size() == int(5e5))
            break;
        for (int j = i; j < N; j += i)
        {
            si[j] = 1;
        }
    }
    int l, h;
    string p;
    cin >> l >> h >> p;
    l--, h--;
    int ans = 0;
    for (int i = 0; i < int(5e5); i++)
    {
        if (i >= l and i <= h)
        {
            ans += int(contains(primes[i], p));
        }
    }
    cout << ans << endl;
}
int main()
{
    fast;
    int tc = 1;
    // cin >> tc;
    while (tc--)
    {
        solve();
    }
}