#include <bits/stdc++.h>
using namespace std;
int a[300005][11];
pair<int, int> check(int n, int m, int mid) {
  vector<pair<string, int> > s;
  unordered_map<string, int> m1;
  for (int i = 1; i <= n; i++) {
    string cur;
    int mn = (int)(1e9 + 7);
    for (int j = 1; j <= m; j++) {
      if (a[i][j] >= mid)
        cur += "1";
      else
        cur += "0";
      mn = min(mn, a[i][j]);
    }
    if (mn >= mid) return {i, i};
    if (!m1[cur]) s.push_back({cur, i}), m1[cur]++;
  }
  vector<pair<string, int> > v(s.begin(), s.end());
  if (v.size() == 1) {
    for (char &c : v[0].first) {
      if (c == '0') return {-1, -1};
    }
    return {v[0].second, v[0].second};
  }
  for (int i = 0; i < v.size(); i++) {
    for (int j = i + 1; j < v.size(); j++) {
      int fl = 1;
      for (int in = 0; in <= m - 1; in++) {
        if (v[i].first[in] == '0' and v[j].first[in] == '0') {
          fl = 0;
          break;
        }
      }
      if (fl == 1) return {v[i].second, v[j].second};
    }
  }
  return {-1, -1};
}
void solve() {
  int n, m;
  cin >> n >> m;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= m; j++) {
      cin >> a[i][j];
    }
  }
  int l = 0, r = (int)(1e9 + 7) - 7;
  pair<int, int> ans;
  while (l <= r) {
    int mid = (l + r) / 2;
    pair<int, int> cur = check(n, m, mid);
    if (cur.first != -1)
      ans = cur, l = mid + 1;
    else
      r = mid - 1;
  }
  cout << ans.first << ' ' << ans.second;
}
int main() {
  std::ios::sync_with_stdio(false);
  cin.tie(NULL);
  int t = 1;
  while (t--) {
    solve();
  }
}
