#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, dif, index;
  cin >> n;
  int h[n];
  for (int i = 0; i < n; i++) cin >> h[i];
  dif = abs(h[0] - h[n - 1]);
  index = n;
  for (int i = 0; i < n - 1; i++) {
    if (abs(h[i] - h[i + 1]) < dif) {
      dif = abs(h[i] - h[i + 1]);
      index = i + 1;
    }
  }
  cout << index << " " << 1 + index % n << endl;
}
