#include <bits/stdc++.h>

using i64 = long long;

constexpr i64 P = i64(1E18) + 9;

std::mt19937_64 rng(114514);

int main() {
	std::ios::sync_with_stdio(false);
	std::cin.tie(nullptr);
	
	int N, M, K;
	std::cin >> N >> M >> K;
	
	std::vector<std::string> S(N);
	for (int i = 0; i < N; i++) {
		std::cin >> S[i];
	}
	
	std::vector<i64> x(N);
	
	i64 sumx = 0;
	for (int i = 0; i < N; i++) {
		x[i] = rng() % P;
		sumx = (sumx + x[i]) % P;
	}
	
	std::vector<std::array<i64, 4>> cnt(M);
	for (int i = 0; i < N; i++) {
		for (int j = 0; j < M; j++) {
			cnt[j][S[i][j] - 'A'] = (cnt[j][S[i][j] - 'A'] + x[i]) % P;
		}
	}
	
	for (int i = 0; i < N; i++) {
		i64 sum = 0;
		for (int j = 0; j < M; j++) {
			sum = (sum + sumx - cnt[j][S[i][j] - 'A'] + P) % P;
		}
		if (sum == (__int128(sumx) - x[i] + P) * K % P) {
			std::cout << i + 1 << "\n";
		}
	}
	
	return 0;
}