#include<bits/stdc++.h>
using namespace std;
#define int long long
typedef pair<int, int> PII;
typedef long long LL;
const int INF = 0x3f3f3f3f3f3f3f3f;

bool multi = 0;

struct Node {
    int i, j, cnt;
};

void solve() {
    int n, m, k;
    cin >> n >> m >> k;
    map<string, Node> mp;
    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= m; j++) {
            char c;
            string s;
            for(int t = 1; t <= k; t++) {
                cin >> c;
                s += c;
            }
            auto x = mp[s];
            // cout << i << ' ' << j << ' ' << s << ' ' << x.cnt << ' ' << x.i << ' ' << x.j << '\n';
            mp[s] = {i, j, x.cnt + 1};
        }
    }
    for(auto [s, x] : mp) {
        if(x.cnt == 1) {
            cout << x.i << ' ' << x.j << '\n';
            return;
        }
    }
}

signed main() {
    ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    int T = 1;
    if(multi) cin >> T;
    while(T--) {
        solve();
    }

    return 0;
}