#include <bits/stdc++.h> #pragma GCC optimize("O3,unroll-loops") #pragma GCC target("avx2") #define int long long #define pii pair<int,int> #define vi vector<int> #define ff first #define ss second #define sp << " " << #define all(x) x.begin(),x.end() #define big(x) ((int)(x.size())) using namespace std; const int MOD = 998244353, LIM = 1e6+1, inf = 2e18,N = 2e5+1; void solve() { int n,m,k; cin >> n >> m >> k; vector<string> strs(n+1); stack<int> stk; auto calcdiff =[&](int i,int j) -> int { int ans = 0; for (int p = 0;p<m;p++) { ans+=strs[i][p] != strs[j][p]; } return ans; }; for (int i=1;i<=n;i++) { cin >> strs[i]; if (!stk.empty() && calcdiff(stk.top(),i) != k) { stk.pop(); continue; } stk.push(i); } for (int i=n;i>=1;i--) { if (!stk.empty() && (stk.top() != i && calcdiff(stk.top(),i) != k)) { stk.pop(); continue; } } cout << stk.top() << '\n'; } signed main() { ios_base::sync_with_stdio(0); cin.tie(0); int t = 1; //cin >> t; while (t --> 0) solve(); }