#include <bits/stdc++.h>
using namespace std;
int main() {
  {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
  };
  int n;
  cin >> n;
  vector<int> d(n);
  for (int i = 0; i < n; i++) {
    cin >> d[i];
  }
  int mn = abs(d[0] - d[n - 1]);
  int l = 0, r = n - 1;
  for (int i = 0; i < n - 1; i++) {
    if (abs(d[i] - d[i + 1]) < mn) {
      mn = abs(d[i] - d[i + 1]);
      l = i;
      r = i + 1;
    }
  }
  cout << l + 1 << " " << r + 1;
}
