#include #include #define rep(i,n) for(int i=0;i vi; typedef vector vl; typedef vector> vvi; typedef vector> vvl; typedef long double ld; typedef pair P; ostream& operator<<(ostream& os, const modint& a) {os << a.val(); return os;} template ostream& operator<<(ostream& os, const static_modint& a) {os << a.val(); return os;} template ostream& operator<<(ostream& os, const dynamic_modint& a) {os << a.val(); return os;} template istream& operator>>(istream& is, vector& v){int n = v.size(); assert(n > 0); rep(i, n) is >> v[i]; return is;} template ostream& operator<<(ostream& os, const pair& p){os << p.first << ' ' << p.second; return os;} template ostream& operator<<(ostream& os, const vector& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : " "); return os;} template ostream& operator<<(ostream& os, const vector>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : ""); return os;} template void chmin(T& a, T b){a = min(a, b);} template void chmax(T& a, T b){a = max(a, b);} // Sieve of Eratosthenes // https://youtu.be/UTVg7wzMWQc?t=2774 struct Sieve { int n; vector f, primes; Sieve(int n=1):n(n), f(n+1) { f[0] = f[1] = -1; for (ll i = 2; i <= n; ++i) { if (f[i]) continue; primes.push_back(i); f[i] = i; for (ll j = i*i; j <= n; j += i) { if (!f[j]) f[j] = i; } } } bool isPrime(int x) { return f[x] == x;} vector factorList(int x) { vector res; while (x != 1) { res.push_back(f[x]); x /= f[x]; } return res; } vector> factor(ll x) { vector> res; for (int p : primes) { int y = 0; while (x%p == 0) x /= p, ++y; if (y != 0) res.emplace_back(p,y); } if (x != 1) res.emplace_back(x,1); return res; } int num_of_divisors(long long x){ auto f = factor(x); long long res = 1; for(auto [p, val] : f){ res *= val + 1; } return res; } set divisors(long long x){ set se = {1}; auto f = factor(x); for(auto [key, value] : f){ set old = se; for(long long y : old){ rep(i, value + 1){ se.insert(y); y *= key; } } } return se; } }; const int M = 200000; int main(){ Sieve sieve(500); int n; cin >> n; vector a(n); cin >> a; auto p = sieve.primes; int m = p.size(); vector> v(M + 1); rep(i, n){ rep(j, m){ bool success = false; while(a[i] % p[j] == 0){ success = true; a[i] /= p[j]; } if(success) v[p[j]].push_back(i); } if(a[i] > 1) v[a[i]].push_back(i); } dsu uf(n); bool two = false; bool three = false; rep(j, M + 1){ int sz = v[j].size(); if(j == 2 and sz >= 1) two = true; if(j == 3 and sz >= 1) three = true; rep(k, sz - 1) uf.merge(v[j][k], v[j][k + 1]); } int sz = uf.groups().size(); if(sz == 1){ cout << "0\n"; return 0; } if(two){ cout << (sz - 1) * 2 << "\n"; return 0; } if(three && sz == 2){ cout << 3 << "\n"; return 0; } cout << 2 * sz << "\n"; return 0; }