Envío 758

Código

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

#define ll long long
#define D(x) cout << #x << " " << x << endl

int main() {
	ll n, right = 0, left = 0, ans = -1;
	cin >> n;
	vector<ll> a(n);
	for(int i = 0; i < n; ++i) {
		cin >> a[i];
		right += a[i];
	}
	for(int i = 0; i < n && ans == -1; ++i) {
		if(left > 0 && right < 0) ans = i;
		left += a[i];
		right -= a[i];
	}
	if(ans == -1) cout << "Impossible" << endl;
	else cout << ans << endl;
	return 0;
}