//#pragma GCC optimize("O3")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define debug(x) cerr << #x << " is " << x << endl;
#define FastIO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define endl '\n'
#define pb push_back
#define F first
#define S second
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define ll long long
#define one(x) __builtin_popcount(x)
#define ld long double
#define sz(x) x.size()
using namespace std;
using namespace __gnu_pbds;
typedef tree<int,null_type,less<int>,rb_tree_tag,
tree_order_statistics_node_update> indexed_set;
const int N = 1400000;
bool prime(int x){
    for(int i = 2; i * i <= x; ++i){
        if(x%i == 0){
            return false;
        }
    }
    return true;
}
void doWork(){
    vector<int> primes;
    for(int i = 2; i < N; ++i){
        if(prime(i)){
            primes.pb(i);
        }
    }
    int l, h;
    cin >> l >> h;
    string s;
    cin >> s;
    l--, h--;
    int answer = 0;
    for(int i = l; i <= h; ++i){
        string t = to_string(primes[i]);
        if(t.find(s) != string::npos){
            //debug(t);
            answer += 1;
        }
    }
    cout << answer << endl;
}
int32_t main(){
    FastIO
    int tc = 1;
    //cin >> tc;
    while(tc--){
        doWork();
    }
    return 0;
}