#include <bits/stdc++.h>
using namespace std;
long long gcd(long long a, long long b) {
  if (a < b)
    return gcd(b, a);
  else if (b == 0)
    return a;
  else
    return gcd(b, a % b);
}
long long pow(long long b, long long e) {
  if (e == 0)
    return 1;
  else if (e % 2 == 0) {
    long long a = pow(b, e / 2);
    return a * a;
  } else {
    long long a = pow(b, e / 2);
    return b * a * a;
  }
}
long long powm(long long x, long long y, long long m = 1000000007) {
  x = x % m;
  long long res = 1;
  while (y) {
    if (y & 1) res = res * x;
    res %= m;
    y = y >> 1;
    x = x * x;
    x %= m;
  }
  return res;
}
long long lcm(long long a, long long b) { return (a * b) / gcd(a, b); }
long long modInverse(long long a, long long m) { return powm(a, m - 2, m); }
bool issq(long long n) {
  long long p = sqrt(n);
  return p * p == n;
}
long long MIN(long long a = 2e18, long long b = 2e18, long long c = 2e18,
              long long d = 2e18, long long e = 2e18) {
  return min(a, min(b, min(c, min(d, e))));
}
long long MAX(long long a = -2e18, long long b = -2e18, long long c = -2e18,
              long long d = -2e18, long long e = -2e18) {
  return max(a, max(b, max(c, max(d, e))));
}
vector<int> prime;
void seive(long long n) {
  prime.resize(n + 5, 0);
  long long j;
  for (long long i = 2; i <= n; i++) {
    if (!prime[i]) {
      prime[i] = i;
      for (j = i * i; j <= n; j += i)
        if (!prime[j]) prime[j] = i;
    }
  }
}
long long extended_GCD(long long a, long long b, long long &x, long long &y) {
  if (a == 0) {
    x = 0;
    y = 1;
    return b;
  }
  long long x1, y1;
  long long gcd = extended_GCD(b % a, a, x1, y1);
  x = y1 - (b / a) * x1;
  y = x1;
  return gcd;
}
long long mulInv(long long a, long long mod) {
  long long x, y;
  extended_GCD(a, mod, x, y);
  if (x < 0) x += mod;
  return x;
}
void __print(int x) { cout << x; }
void __print(long x) { cout << x; }
void __print(long long x) { cout << x; }
void __print(unsigned x) { cout << x; }
void __print(unsigned long x) { cout << x; }
void __print(unsigned long long x) { cout << x; }
void __print(float x) { cout << x; }
void __print(double x) { cout << x; }
void __print(long double x) { cout << x; }
void __print(char x) { cout << "'" << x << "'"; }
void __print(const char *x) { cout << '"' << x << '"'; }
void __print(const string &x) { cout << '"' << x << '"'; }
void __print(bool x) { cout << (x ? "true" : "false"); }
template <typename T, typename V>
void __print(const pair<T, V> &x) {
  cout << '{';
  __print(x.first);
  cout << ',';
  __print(x.second);
  cout << '}';
}
template <typename T>
void __print(const T &x) {
  int f = 0;
  cout << '{';
  for (auto &i : x) cout << (f++ ? "," : ""), __print(i);
  cout << "}";
}
void _print() { cout << "]\n"; }
template <typename T, typename... V>
void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v)) cout << ", ";
  _print(v...);
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  long long n;
  cin >> n;
  long long a[n + 1];
  long long f = 0;
  for (long long i = 1; i <= n; i++) {
    cin >> a[i];
    if (a[1] != a[i]) f = 1;
  }
  if (f == 0)
    cout << -1;
  else {
    long long d = 15e6;
    seive(d);
    long long hcf = a[1];
    for (long long i = 2; i <= n; i++) hcf = gcd(hcf, a[i]);
    map<long long, long long> mp;
    for (long long i = 1; i <= n; i++) {
      a[i] = a[i] / hcf;
      long long x = a[i];
      while (x != 1) {
        long long p = prime[x];
        mp[p]++;
        while (x % p == 0) x /= p;
      }
    }
    long long ans = 0;
    for (auto x : mp) ans = max(ans, x.second);
    cout << n - ans;
    cout << "\n";
  }
  return 0;
}
