1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
#include <bits/stdc++.h>
using namespace std;

int n;
vector<int> v;
int ending[100009];
bool marked[100009];
bool check(int k) {
    for (int i = 0; i<n; i++) {
        ending[i] = 0;
    }
    int active = 0;
    for (int i = 0; i < n; i++) {
        if (active < v[i] and i+k-1 < n) {
            ending[i+k-1] += v[i]-active;
            active = v[i];
        }
        if (active != v[i]) {
            return false;
        }
        active -= ending[i];
    }
    return true;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin >> n;
    for (int i = 0; i < n; i++) {
        int x;
        cin >> x;
        v.push_back(x);
    }
    int best = 0;
    for (int i = 1; i<=n; i++) {
        if (!marked[i]) {
            if (!check(i)) {
                marked[i] = true;
                for (int j = i+i; j<=n; j+=i) {
                    marked[j] = true;
                }
            }else {
                best = i;
            }
        }
    }
    cout << best << "\n";
}