#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;

void solve() {
    int n, m, k;
    cin >> n >> m >> k;
    string tmp;
    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;
            }
            if(tmp.size() == 0) {
                tmp = s;
            }else if(tmp != s) {
                cout << i << ' ' << 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;
}