#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int first;
  int n;
  cin >> n;
  int i;
  vector<int> nums(n);
  for (i = 0; i < n; ++i) {
    cin >> nums[i];
  }
  int minDiff = abs(nums[n - 1] - nums[0]);
  int idx = n - 1;
  for (i = 0; i < n - 1; ++i) {
    int t = abs(nums[i + 1] - nums[i]);
    if (t < minDiff) {
      minDiff = t;
      idx = i;
    }
  }
  if (idx == n - 1)
    cout << n << ' ' << 1 << endl;
  else
    cout << idx + 1 << ' ' << idx + 2 << endl;
  return 0;
}
