#include <bits/stdc++.h>
using namespace std;
mt19937 rng(chrono::high_resolution_clock
::now().time_since_epoch().count());
const int N = 4005;
const int MOD = 1e9 + 9;
string s[N];
int n, m, k, num[N], sum[N][4];
int add(int x, int y) {
return (x += y) >= MOD ? x - MOD : x;
}
int mul(int x, int y) {
return (long long)x * y % MOD;
}
int sub(int x, int y) {
return (x -= y) < 0 ? x + MOD : x;
}
int index(char c) {
if (c == 'A') return 0;
if (c == 'C') return 1;
if (c == 'G') return 2;
return 3;
}
int rand(int l, int r) {
return uniform_int_distribution<int> (l, r)(rng);
}
int main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n >> m >> k;
for (int i = 0; i < n; i++) {
cin >> s[i]; num[i] = rand(0, MOD - 1);
for (int j = 0; j < m; j++)
sum[j][index(s[i][j])] = add
(sum[j][index(s[i][j])], num[i]);
}
vector<int> can;
for (int i = 0; i < n; i++) {
int tmp = 0;
for (int j = 0; j < m; j++)
for (int c = 0; c < 4; c++)
if (index(s[i][j]) != c)
tmp = add(tmp, sum[j][c]);
for (int j = 0; j < n; j++)
if (i != j) tmp = sub(tmp, mul(num[j], k));
if (!tmp) cout << i + 1;
}
}
