#include<cmath>

#include<set>

#include<map>

#include<queue>

#include<cstdio>

#include<vector>

#include<cstring>

#include <iostream>

#include<algorithm>

#include<unordered_map>

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

const int maxn = 3e5 + 10;

const int M = 1.5 * 1e7 + 10;

const ull seed = 131;

const int INF = 0x3f3f3f3f;

const int MOD = 1e4 + 7;

int gcd(int a, int b){

    return b == 0? a : gcd(b, a % b);

}

int a[maxn];

int p[4000], prime[4000], pn;

int num[M];

void init(){

    pn = 0;

    memset(p, 0, sizeof(p));

    for(int i = 2;  i < 4000; i++){

        if(!p[i]){

            prime[pn++] = i;

        }

        for(ll j = 0; j < pn && i * prime[j] < 4000; j++){

            p[i * prime[j]] = 1;

            if(i % prime[j] == 0) continue;

        }

    }

//    printf("%d\n", pn);

}

int main(){

    int n, need;

    init();

    scanf("%d", &n);

    memset(num, 0, sizeof(num));

    for(int i = 1; i <= n; i++){

        scanf("%d", &a[i]);

        if(i == 1) need = a[i];

        else need = gcd(need, a[i]);

    }

    for(int i = 1 ; i <= n; i++) a[i] /= need;

    int ans = -1;

    for(int i = 1; i <= n; i++){

        for(int j = 0; j < pn && prime[j] * prime[j] <= a[i]; j++){

            if(a[i] % prime[j] == 0){

                num[prime[j]]++;

                ans = max(ans, num[prime[j]]);

                while(a[i] % prime[j] == 0) a[i] /= prime[j];

            }

        }

        if(a[i] > 1){

            num[a[i]]++;

            ans = max(ans, num[a[i]]);

        }

    }

    if(ans == -1) printf("%d\n", ans);

    else printf("%d\n", n - ans);

    return 0;

}