#include <bits/stdc++.h>
using namespace std;
int main() {
  vector<int> data;
  int N, i, a, min = 999999999, first, second;
  cin >> N;
  for (i = 0; i < N; i += 1) {
    cin >> a;
    data.push_back(a);
  }
  for (i = 0; i < N - 1; i += 1) {
    if (abs(data[i] - data[i + 1]) < min) {
      min = abs(data[i] - data[i + 1]);
      first = i + 1;
      second = i + 2;
    }
  }
  if (abs(data[0] - data[N - 1]) < min) {
    min = abs(data[0] - data[N - 1]);
    first = N;
    second = 1;
  }
  cout << first << " " << second << endl;
}
