#define _CRT_SECURE_NO_WARNINGS 1
#pragma GCC optimize(3,"Ofast","inline")
#include<bits/stdc++.h>
typedef long long i64;
typedef long double ld;
#define endl "\n"
#define all(a) a.begin(), a.end()
#define int i64
typedef std::pair<int, int> PII;
const int N = 2e5 + 10;
const int mod = 1e9 + 7;
const int INF = 0x3f3f3f3f;
long long fast_power(i64 a, i64 b, i64 v = mod) {
	i64 sum = 1;
	a = a % v;
	while (b) {
		if (b & 1) {
			sum = sum * a % v;
		}
		a = (a * a) % v;
		b >>= 1;
	}
	return sum;
}
int lowbit(int x) {
	return x & -x;
}
bool is_prime(int n){
    if(n < 2) return false;
    for(int i = 2;i <= n / i;i ++){ 
        if(n % i == 0){
            return false;
        }
    }
    return true;
}
int inv(int x, int m = mod) {
    return fast_power(x, m - 2, m);
}

void solve(){
    int n, m, k;
    std::cin >> n >> m >> k;
    std::string s[n];
    for(int i = 0; i < n; i++) {
        std::cin >> s[i];
    }
    int flag = 0;
    std::map<std::string, int> mp;
    for(int i = 0; i < n; i++) {
        std::string tmp;
        for(int j = 0; j < m * k; j++) {
            tmp += s[i][j];
            if(tmp.size() == k) {
                mp[tmp] ++;
                tmp.clear();
            }
        }
    }
    std::string tmp;
    for(auto [x, y] : mp) {
        if(y == 1) {
            tmp = x;
        }
    }
    // std::cout << tmp;
    for(int i = 0; i < n; i++) {
        std::string tmp2;
        for(int j = 0; j < m * k; j++) {
            tmp2 += s[i][j];
            if(tmp2.size() == k) {
                if(tmp2 == tmp) {
                    std::cout << i + 1 << " " << (j + 1) / k;
                }
                tmp2.clear();
            }
        }
    }
}

signed main() {
#ifndef ONLINE_JUDGE
    freopen("D:/vsc/c/.cph/in.txt", "r", stdin);
	// freopen("D:/vsc/c/.cph/out.txt", "w", stdout);
#else
    std::cin.tie(0);
    std::cout.tie(0);
    std::ios::sync_with_stdio(false);
#endif
	int t = 1;
    // std::cin >> t;
    while(t--) {
        solve();
    }
    
	

}
/*
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*/