#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<bits/stdc++.h>
using namespace std;
int n,m,K;
char s[202][2002];
char f[202];


int main(){
	//freopen("a.in","r",stdin);
	//freopen("a.out","w",stdout);
	scanf("%d %d %d\n",&n,&m,&K);
	
	for(int i=1;i<=n;i++){
		scanf("%s",s[i]+1);
		//cout<<s[i]<<endl;
	}
		
		
	for(int i=1;i<=K;i++){
		
		f[i]=s[1][i];
		//cout<<f[i];
	}
		
	//for(int i=1;i<=K;i++){
		//cout<<f[i];
	//}
	//cout<<f<<endl;
	
	
	int id1=0,id2=0,flag=0,dif=0;
	
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			int flag=0;
			for(int k=1;k<=K;k++){
				//cout<<s[i][(j-1)*K+k];
				if(s[i][(j-1)*K+k]!=f[k]){
					flag=1;
					id1=i;
					id2=j;
				}
			}
			//cout<<' ';
			if(flag==1) 
			   dif++; 
		}
		//cout<<endl;
	}
	
	//cout<<dif<<' ';
	
	if(dif==1)
	   cout<<id1<<' '<<id2;
	else 
	   cout<<1<<' '<<1;
	return 0;
}

/*
3 5 3
QwQQWQQWQQWQQWQ
QWQQWQQWQQWQQWQ
QWQQWQQWQQWQQWQ

*/