#include<bits/stdc++.h>
using namespace std;
using ll = long long;
void solve() {
	ll n, m, k;
	cin >> n >> m >> k;
	map<string, int>mp;
	map<string, pair<ll, ll>>pos;
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= m; j++) {
			string now;
			for (int w = 1; w <= k; w++) {
				char ch;
				cin >> ch;
				now += ch;
			}
			mp[now]++;
			pos[now] = {i, j};
		}
	}
	for (auto &[a, b] : mp) {
		if (b == 1) {
			auto [x,y]=pos[a];
			cout<<x<<" "<<y;
			return;
		}
	}

}
int main() {
	ios::sync_with_stdio(false); cin.tie(0);
	int t = 1;
	// cin>>t;
	while (t--)solve();
}