#include <bits/stdc++.h>

using namespace std;

#define int long long

int n;
bool check = false;
main() {
  //freopen(".inp", "r", stdin);
  //freopen(".out", "w", stdout);
  ios_base::sync_with_stdio(0);
  cin.tie(nullptr);
  cin >> n;
  vector<int> a(n);
  for (int i = 0; i < n; ++i)
  {
    cin >> a[i];
  }
  for (int i = 0; i < n; ++i)
  {
    if (a[i] > 0) 
    {
      cout << i + 1;
      check = true;
      break;
    }
  }
  cout << ' ';
  for (int i = n; i > 0; --i)
  {
    if (a[i] > 0)
    {
      cout << i + 1;
      check = true;
      break;
    }
  }
  if (!check)cout << "-1 -1";
  return 0;
}
    

n=int(input())
a=[0]+list(map(int,input().split()))
s=False
for i in range(1,n+1):
    if a[i]>0:
        l=i
        s=True
        break
for i in range(n,0,-1):
    if a[i]>0:
        r=i
        break
if s:
    print(l,r)
else:
    print(-1,-1)