#include <bits/stdc++.h>
using namespace std;
#define int long long
const int N = 1e6 + 10;
#define pii pair<int, int>
#define lowbit(x) (x & (-x))
int n, m, k;
void solve()
{
    map<string, vector<pair<int, int>>> mp;
    int r1, r2;
    cin >> n >> m >> k;
    for (int i = 1; i <= n; i++)
    {
        for (int j = 1; j <= m; j++)
        {
            string str = "";
            for (int o = 1; o <= k; o++)
            {
                char c;
                cin >> c;
                str += c;
            }
            mp[str].push_back({i, j});
        }
    }
    for (auto t : mp)
    {
        if (t.second.size() == 1)
        {
            cout << t.second[0].first << ' ' << t.second[0].second << endl;
        }
    }
}
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int t = 1;
    // cin >> t;
    while (t--)
        solve();
}