#include <iostream>
using namespace std;

int main() {
int n;
cin >> n;
int a[n];
for(int i = 0; i < n; i++) {
cin >> a[i];
}
int L = 0;
int R = n - 1;
int number_of_merges = 0;
while(L <= R) {
if(a[L] == a[R]) {
L++;
R--;
}
else if(a[L] < a[R]) {
L++;
a[L] += a[L - 1];
number_of_merges++;
}
else {
R--;
a[R] += a[R + 1];
number_of_merges++;
}
}
cout << number_of_merges << endl;
return 0;
}