D

#include <bits/stdc++.h>

using namespace std;

#define ll     long long

int main()
{
    int n;
    string s, t;

    cin>>n>>s;

    vector<int> cnt(10);
    vector<int> cnt2(10);

    for(auto e: s)      cnt[e-'0']++;

    int ans = 0;

    for(ll int i=0, x; i<=1e7; i++)
    {
        x = i*i;

        fill(cnt2.begin(), cnt2.end(), 0);

        t = to_string(x);

        for(auto e: t)      cnt2[e-'0']++;

        cnt2[0] = max(cnt2[0], cnt[0]);

        if(cnt == cnt2)     ans++;
    }

    cout<<ans<<"\n";
}