#include<bits/stdc++.h>
using namespace std;
using i64=long long;
using u64=unsigned long long;
#define ll long long
const int inf=1e9;
const ll inff=1e18;
using i128=__int128;

void solve(){
    int n,m,k;
    cin>>n>>m>>k;
    vector<string> s(n);
    for(int i=0;i<n;i++){
        cin>>s[i];
    }
    string t;
    if(s[0].substr(0,k)==s[0].substr(k,k)){
        t=s[0].substr(0,k);
    }else{
        if(s[0].substr(0,k)!=s[1].substr(0,k)){
            cout<<1<<' '<<1<<'\n';
            return;
        }else{
            cout<<1<<' '<<2<<'\n';
            return;
        }
    }
    for(int i=0;i<n;i++){
        for(int j=0;j<m*k;j+=k){
            if(s[i].substr(j,k)!=t){
                cout<<i+1<<' '<<j/k+1<<'\n';    
                return;
            }
        }
    }
}

int main(){
    ios::sync_with_stdio(0);cin.tie(0);
    int t=1;
    // cin>>t; 
    while(t--){
        solve();
    }
    return 0;
}