//Dedicated to my love, ivaziva
#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
#define int long long
using pii = pair<int, int>;
using ll = int64_t;
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define dbg(x) cerr<<#x<<": "<<x<<'\n';
#define dbga(A,l_,r_){for(int i_=l_;i_<=r_;i_++)cerr<<A[i_]<<' ';cerr<<'\n';}
#define dbgv(a_){for(auto x_:a_) cerr<<x_<<' ';cerr<<'\n';}
const int maxn = 105;
int n, m, k;
string a[maxn];
int32_t main() {
ios::sync_with_stdio(false); cin.tie(nullptr);
cout.tie(nullptr); cerr.tie(nullptr);
cin >> n >> m >> k;
for (int i = 1; i <= n; i++) {
cin >> a[i];
}
int ans = 0;
for (int i = 1; i <= n; i++) {
bool ok = true;
for (int j = 1; j <= n; j++) {
if (i == j) {
continue;
}
int cnt = 0;
for (int p = 0; p < m; p++) {
if (a[i][p] != a[j][p]) {
cnt++;
}
}
if (cnt != k) {
ok = false;
}
}
if (ok) {
ans = i;
}
}
assert(ans != 0);
cout << ans << '\n';
return 0;
}
