#include <bits/stdc++.h>
using namespace std;
int n;
int a[110];
int main() {
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
  }
  a[n + 1] = a[1];
  int x = 1, y = 2;
  int gap = 3000;
  for (int i = 1; i <= n; i++) {
    if (abs(a[i] - a[i + 1]) < gap) {
      gap = abs(a[i] - a[i + 1]);
      x = i;
      y = i + 1;
      if (i == n) {
        y = 1;
      }
    }
  }
  cout << x << " " << y << endl;
}
