#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
template <class T>
inline void arin(T* st, T* nd) {
  while (st < nd) cin >> *st++;
}
int di[] = {1, -1, 0, 0, 1, -1, 1, -1};
int dj[] = {0, 0, 1, -1, 1, -1, -1, 1};
int diK[] = {-2, -2, -1, 1, 2, 2, 1, -1};
int djK[] = {-1, 1, 2, 2, 1, -1, -2, -2};
bool cmd(pair<pair<int, int>, int> a, pair<pair<int, int>, int> b) {
  return (a.first.second < b.first.second);
}
int main() {
  int n;
  cin >> n;
  int a[n];
  arin(a, a + n);
  int l = 0, r = -1, def = 1e6;
  for (int j = 0; j < n; j++) {
    if (abs(a[j % n] - a[(j + 1) % n]) < def)
      l = j, r = (j + 1) % n, def = abs(a[j] - a[(j + 1) % n]);
  }
  cout << l + 1 << " " << r + 1;
}
