#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef unsigned long long int ull;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll myRand(ll B) { return (ull)rng() % B; }
inline double time() {
    return static_cast<long double>(chrono::duration_cast<chrono::nanoseconds>(chrono::steady_clock::now().time_since_epoch()).count()) * 1e-9;
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n, m, k;
    cin >> n >> m >> k;
    map<string, vector<pair<int, int>>> mp;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < m; ++j) {
            string s;
            for (int l = 0; l < k; ++l) {
                char c;
                cin >> c;
                s.push_back(c);
            }
            mp[s].push_back({i, j});
        }
    }
    for (auto p : mp) {
        if (p.second.size() == 1) {
            cout << p.second[0].first + 1 << " " << p.second[0].second + 1 << '\n';
        }
    }
}