#include<bits/stdc++.h>
#define rep2(i,j,k) for(ll i = ll(j); i < ll(k); i++)
#define rep(i,k) rep2(i,0,k)
#define rrep2(i,j,k) for(ll i = ll(j)-1; i >= ll(k); i--)
#define rrep(i,k) rrep2(i,k,0)
#define SZ(a) ll(a.size())
#define eb emplace_back
#define all(a) a.begin(), a.end()

using namespace std;
using ll = long long;
using P = pair<ll,ll>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vp = vector<P>;
using vvp = vector<vp>;

bool chmax(auto& a, auto b) {return a < b ? a = b, 1 : 0; }
bool chmin(auto& a, auto b) {return a > b ? a = b, 1 : 0; }

int main(){
	cin.tie(0) -> sync_with_stdio(0);
	int n, m, k;
	cin >> n >> m >> k;
	map<string, vp> mp;
	rep(i, n) rep(j, m) {
		string s;
		rep(_, k) {
			char c;
			cin >> c;
			s.push_back(c);
		}
		mp[s].eb(i+1, j+1);
	}
	for(auto [_, v] : mp) {
		if(SZ(v) == 1) {
			cout << v[0].first << ' ' << v[0].second << '\n';
			return 0;
		}
	}
}