#include <bits/stdc++.h>
using namespace std;
const int N = 3e4 + 7, M = 2e2 + 7;
bool fl[N];
int n, k, tot, fs[N], sum[N], pos[M], f[M][N];
map<int, bool> s[N];
struct edge {
  int u, v;
} ed[N * M];
struct node {
  int ch[M], num;
} qt[N];
inline int read() {
  int num = 0;
  char g = getchar();
  while (g < 48 || 57 < g) g = getchar();
  while (47 < g && g < 58)
    num = (num << 1) + (num << 3) + g - 48, g = getchar();
  return num;
}
inline int find(int u) {
  if (fs[u] == u) return u;
  return fs[u] = find(fs[u]);
}
inline bool equals(node a, node b) {
  for (int i = 1; i <= k; i++)
    if (a.ch[i] + 1 != b.ch[i]) return false;
  return true;
}
inline bool cmp(node a, node b) {
  for (int i = 1; i <= k; i++) {
    if (a.ch[i] < b.ch[i]) return false;
    if (a.ch[i] > b.ch[i]) return true;
  }
  return false;
}
int main() {
  n = read(), k = read();
  for (int i = 1; i <= k; i++)
    for (int x = 1; x <= n; x++) f[i][x] = read();
  for (int i = 1; i <= k; i++)
    for (int x = 1; x <= n; x++)
      if (!f[i][x]) pos[i] = x;
  for (int i = 2; i <= k; i++) {
    memset(sum, 0, sizeof(sum));
    for (int c = 1; c <= n; c++)
      if (f[i][c] + f[1][c] == f[1][pos[i]]) sum[f[1][c]] = c;
    for (int c = 0; c <= f[1][pos[i]]; c++)
      if (!sum[c]) {
        puts("-1");
        return 0;
      }
    for (int c = 0; c < f[1][pos[i]]; c++)
      if (!s[sum[c]][sum[c + 1]])
        s[sum[c]][sum[c + 1]] = s[sum[c + 1]][sum[c]] = 1, ed[++tot].u = sum[c],
                          ed[tot].v = sum[c + 1];
  }
  for (int i = 1; i <= n; i++) fs[i] = i;
  for (int i = 1; i <= tot; i++) {
    int a = ed[i].u, b = ed[i].v;
    fl[a] = fl[b] = 1, fs[a] = find(a), fs[b] = find(b);
    if (fs[a] == fs[b]) {
      puts("-1");
      return 0;
    }
    fs[fs[a]] = find(b);
  }
  int tp = 1;
  for (int x = 1; x <= n; x++) {
    qt[x].num = x;
    for (int i = 1; i <= k; i++) qt[x].ch[i] = f[i][x];
  }
  for (int i = 1; i <= k; i++) fl[pos[i]] = 1;
  sort(qt + 1, qt + n + 1, cmp);
  for (int i = 1; i <= n; i++) {
    int c = qt[i].num;
    if (fl[c]) continue;
    while ((!equals(qt[tp], qt[i])) && tp <= n) tp++;
    if (tp > n) {
      puts("-1");
      return 0;
    }
    tot++, ed[tot].u = c, ed[tot].v = qt[tp].num;
  }
  for (int i = 1; i <= tot; i++) printf("%d %d\n", ed[i].u, ed[i].v);
  return 0;
}
