#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int amountof_soldier;
  cin >> amountof_soldier;
  int soldier_heights[amountof_soldier];
  for (int i = 0; i < amountof_soldier; i++) {
    cin >> soldier_heights[i];
  }
  int min_heightdiff = abs(soldier_heights[0] - soldier_heights[1]);
  for (int i = 1; i < (amountof_soldier - 1); ++i) {
    if (abs(soldier_heights[i] - soldier_heights[i + 1]) < min_heightdiff) {
      min_heightdiff = abs(soldier_heights[i] - soldier_heights[i + 1]);
    }
  }
  if (min_heightdiff <
      abs(soldier_heights[0] - soldier_heights[amountof_soldier - 1])) {
    for (int i = 0; i < (amountof_soldier - 1); ++i) {
      if (abs(soldier_heights[i] - soldier_heights[i + 1]) == min_heightdiff) {
        cout << (i + 1) << " " << (i + 2) << endl;
        break;
      }
    }
  } else if (min_heightdiff >=
             abs(soldier_heights[0] - soldier_heights[amountof_soldier - 1])) {
    cout << 1 << " " << amountof_soldier << endl;
  }
  return 0;
}
