#include <cstdio>
#include <algorithm>
#include <vector>
#include <utility>

using namespace std;

const int max1 = 200, max2 = 10;

int n, m, k;
char s[max1 + 5][max1 * max2 + 5];

vector < pair <int, int> > bin;

bool Cmp ( int a, int b, int c, int d, int len )
{
    for ( int i = 1; i <= len; i ++ )
        if ( s[a][b + i - 1] != s[c][d + i - 1] )
            return false;
    return true;
}

int main ()
{
    scanf("%d%d%d", &n, &m, &k);
    for ( int i = 1; i <= n; i ++ )
        scanf("%s", s[i] + 1);
    
    for ( int i = 1; i <= n; i ++ )
    {
        for ( int j = 1; j <= m * k; j += k )
        {
            if ( i == 1 && j == 1 )
                continue;

            if ( !Cmp(1, 1, i, j, k) )
                bin.push_back(make_pair(i, (j - 1) / k + 1));
        }
    }

    if ( bin.size() == 1 )
        printf("%d %d\n", bin[0].first, bin[0].second);
    else
        printf("1 1\n");

    return 0;
}