#include <bits/stdc++.h>
using namespace std;

int main() {
    int n, m, k; cin >> n >> m >> k;
    vector<string> s(n);
    for (auto &s: s) cin >> s;
    vector<string> sk;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            sk.push_back(s[i].substr(j * k, k));
        }
    }
    sort(sk.begin(), sk.end());
    string diff;
    if (sk[0] != sk[1]) diff = sk[0];
    else diff = sk.back();

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if (s[i].substr(j * k, k) == diff) {
                cout << i + 1 << " " << j + 1 << endl;
            }
        }
    }
}