#include <bits/stdc++.h>
using namespace std;
const long long N = 1e5 + 10;
long long n, a[110], t, mn = 1e18;
int main() {
  cin >> n;
  for (int i = 1; i <= n; i++) cin >> a[i];
  a[0] = a[n];
  for (int i = 1; i <= n; i++) {
    if (mn > abs(a[i] - a[i - 1])) {
      mn = abs(a[i] - a[i - 1]);
      t = i;
    }
  }
  if (t == 1) {
    cout << n << " " << 1;
  } else {
    cout << t - 1 << " " << t;
  }
}
