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#include<bits/stdc++.h>
using namespace std;
using ll = long long;
constexpr ll MAXN = 1e5+2;
bool prim[MAXN];
ll add[2*MAXN];
ll A[2*MAXN], B[MAXN];
int n;
int dasie[2*MAXN];
ll sum;

void sito() {
  for(ll i = 2; i < MAXN; ++i) {
    if(!prim[i]) for(ll j = i*i; j < MAXN; j += i) prim[j] = true;
  }
}

bool sym(int d) {
  for(int i = 1; i <= n; ++i) add[i] = 0;
  int cur{};
  for(int i = 1; i <= n-d+1; ++i) {
    cur += add[i];
    if(A[i] - cur < 0) return false;
    add[i+d] -= A[i]-cur;
    cur += A[i]-cur;
  }
  for(int i = n-d+2; i <= n; ++i) {
    cur += add[i];
    if(A[i] - cur != 0) return false;
  }
  return true;
}

void prepro() {
  for(ll i = 2; i <= 314; ++i) {
    if(prim[i]) continue;
    ll j = i;
    do {
      if(sum%j) dasie[j] = 1;
      dasie[j] = sym(j)+1;
      if(dasie[j] == 1) {
        for(ll x = j+j; x < MAXN; x += j) dasie[x] = 1;
      }
      j *= i;
    } while(j < MAXN);
  }
}



int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  sito();
  cin >> n;
  for(int i = 1; i <= n; ++i) {
    cin >> A[i];
    sum += A[i];
  }
  prepro();
  ll ans{};
  for(ll i = n; i >= 2; --i) {
    if(sum%i) continue;
    if(!dasie[i]) dasie[i] = sym(i)+1;
    if(dasie[i] == 2) {
      ans = i;
      break;
    }
  }
  cout << max(ans, 1ll) << '\n';
}