#include <bits/stdc++.h>
int main() {
  int n;
  scanf("%d\n", &n);
  int* heights = new int[n];
  for (int k = 0; k < n; k++) {
    scanf("%d", heights + k);
  }
  int absDiff(abs(heights[0] - heights[n - 1])), index(n - 1);
  for (int k = 0; k < n - 1; k++) {
    if (abs(heights[k] - heights[k + 1]) < absDiff) {
      absDiff = abs(heights[k] - heights[k + 1]);
      index = k;
    }
  }
  printf("%d %d\n", 1 + index, 1 + (index + 1) % n);
  return 0;
}
