#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, i, small, index = 0;
  int x[101];
  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> x[i];
  }
  x[n] = x[0];
  small = abs(x[0] - x[1]);
  for (i = 0; i < n; i++) {
    if (small > abs(x[i] - x[i + 1])) {
      small = abs(x[i] - x[i + 1]);
    }
  }
  for (i = 0; i < n; i++) {
    if (small == abs(x[i] - x[i + 1])) {
      index = i;
      break;
    }
  }
  if (index == n - 1) {
    printf("%d %d", index + 1, 1);
  } else {
    printf("%d %d", index + 1, index + 2);
  }
  return 0;
}
