ソースコード
#include "iostream"
#include "climits"
#include "list"
#include "queue"
#include "stack"
#include "set"
#include "functional"
#include "algorithm"
#include "math.h"
#include "utility"
#include "string"
#include "map"
#include "unordered_map"
#include "iomanip"
#include "random"
using namespace std;
const long long int MOD = 1000000007;
long long int power(long long int x, long long int n, long long int M) {
long long int tmp = 1;
if (n > 0) {
tmp = power(x, n / 2, M);
if (n % 2 == 0) tmp = (tmp*tmp) % M;
else tmp = (((tmp*tmp) % M)*x) % M;
}
return tmp;
}
long long int N, M, K, Q, W, H, L, R;
long long int ans;
int main() {
ios::sync_with_stdio(false);
cin >> N;
ans = -1;
long long int num[100001] = {};
for (int i = 1; i <= N; i++)cin >> num[i];
for (int i = 1; i <= N; i++)num[i] += num[i - 1];
for (int i = 1; i <= N; i++) {
if (num[i] - num[0] >= 0)ans = i;
}
for (int i = N; i >= 1; i--) {
if (num[N] - num[i - 1] >= 0)ans = max(ans, N - i + 1);
}
cout << ans << endl;
return 0;
}