/**
* author: wxhtzdy
* created: 10.11.2022 15:59:08
**/
#include <bits/stdc++.h>
using namespace std;
string c = "ACGT";
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n, m, k;
cin >> n >> m >> k;
vector<string> s(n);
for (int i = 0; i < n; i++) {
cin >> s[i];
}
vector<int> order(n);
iota(order.begin(), order.end(), 0);
mt19937 rng(31413113);
shuffle(order.begin(), order.end(), rng);
const int N = 4100;
vector<vector<bitset<N>>> f(n, vector<bitset<N>>(4));
for (int i = 0; i < 2; i++) {
for (int j : order) {
for (int k = 0; k < m; k++) {
f[j][i][k] = (c[i] == s[j][k] ? 1 : 0);
}
}
}
vector<vector<int>> d(n, vector<int>(n));
vector<bool> is(n, true);
for (int ii = 0; ii < n; ii++) {
int i = order[ii];
for (int jj = ii + 1; jj < n; jj++) {
int j = order[jj];
if (!is[i] && !is[j]) {
continue;
}
d[i][j] += (f[i][0] ^ f[j][0]).count() + (f[i][1] ^ f[j][1]).count();
if (d[i][j] != k * 2) {
is[i] = false;
is[j] = false;
}
}
if (is[i]) {
cout << i + 1 << '\n';
return 0;
}
}
for (int i = 0; i < n; i++) {
for (int j = i + 1; j < n; j++) {
if (d[i][j] != k * 2) {
is[i] = false;
is[j] = false;
}
}
}
for (int i = 0; i < n; i++) {
if (is[i]) {
cout << i + 1 << '\n';
}
}
return 0;
}
