#include <bits/stdc++.h>
using namespace std;
vector<int> army;
int main() {
  int n, z;
  cin >> n;
  for (int i = 0; i < n; ++i) {
    cin >> z;
    army.push_back(z);
  }
  int x, y;
  int min = 100000;
  for (int i = 0; i < n; ++i) {
    for (int j = 1; j < n; ++j) {
      if (i == j) continue;
      if ((i == j + 1) || (i == j - 1) || (j == i + 1) || (j == j - 1) ||
          ((i == 0) && (j == n - 1))) {
        if (abs(army[i] - army[j]) < min) {
          min = abs(army[i] - army[j]);
          x = i + 1;
          y = j + 1;
        }
      }
    }
  }
  cout << x << " " << y;
  return 0;
}
