#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = false;
//---------------------------------//

std::vector<ll> find_divisor(ll n) {
	assert(n > 0);
	std::vector<ll> divisor;
	ll i = 1;
	for (; i * i <= n; i++) if (n % i == 0) divisor.emplace_back(i);
	int p = divisor.size() - 1;
	if (divisor[p] * divisor[p] == n) --p;
	for (; p >= 0; --p) divisor.emplace_back(n / divisor[p]);
	return divisor;
}

int main() {
	int N;
	cin >> N;
	vector<int> A(N);
	REP(i, N) scanf("%d", &A[i]);
	const int s = accumulate(ALL(A), 0);
	for (int d : find_divisor(s)) {
		int cnt = 0, sum = 0;
		REP(i, N) {
			sum += A[i];
			if (sum > d) { cnt = -1; break; }
			if (sum == d) { ++cnt; sum = 0; }
		}
		if (sum > 0) cnt = -1;
		if (cnt == -1) continue;
		printf("%d\n", cnt);
		return 0;
	}
}