# define _CRT_SECURE_NO_WARNINGS 1
# define _USE_MATH_DEFINES
# include <iostream>
# include <numeric>
# include <string>
# include <bitset>
# include <vector>
# include <algorithm>
# include <cstdlib>
# include <cstdio>
# include <cstring>
# include <cstdlib>
# include <iomanip>
# include <queue>
# include <sstream>
# include <climits>
# include <complex>
# include <cmath>
# include <list>
# include <functional>
# include <string>
# include <ctime>
# include <set>
# include <forward_list>
# include <map>
# include <stack>
using namespace std;
# define INF ((int)(1<<25))
# define REP(i,n) for(int i=0;i<(int)n;i++)
# define FOR(i,n) REP(i,n)
# define FORI(i,k,n) for(int i=k;i<(int)n;i++)
# define TORAD 2.0*M_PI/360.0
# define INT(x) int x;cin>>x;
# define ALL(x) begin(x),end(x)
# define RALL(x) (x).rbegin(),(x).rend()
# define DEBUG(x) cout<<#x<<":"<<x<<endl;
# define EPS 1e-12
#ifdef _MSC_VER
#include <intrin.h>
#define __builtin_popcount __popcnt
#endif
typedef long long lint;
typedef vector<int> vi;
typedef vector<string> vs;
typedef vector<bool> vb;
typedef vector<char> vc;
typedef pair<int, int> pii;
typedef pair<int, pii> piii;
const int dx[4] = { 0,1,0,-1 }, dy[4] = { -1,0,1,0 };
template<class T> void debug(T a) { for (auto i : a)cout << i << endl; }


typedef vector<vc> P;
int h, w, n;
bool check(P &a)
{
	int ans = 0;
	FORI(i, 1, h + 1)
	{
		FORI(j, 1, w + 1)
		{
			if (a[i][j] != '.')ans++;
		}
	}
	return !ans;
}

bool remove(P &a)
{
	bool r[40][40] = {};
	FORI(i, 1, h + 1)
	{
		FORI(j, 1, w + 1)
		{
			if (a[i][j] != '.')
			{
				int c = 0;
				char ch = a[i][j];
				for (int x = j;; x++)
				{
					if (a[i][x] == ch)c++;
					else break;
				}
				if (c >= n)
				{
					for (int x = j;; x++)
					{
						if (a[i][x] == ch)r[i][x] = true;
						else break;
					}
				}
				c = 0;
				for (int y = i;; y++)
				{
					if (a[y][j] == ch)c++;
					else break;
				}
				if (c >= n)
				{
					for (int y = i;; y++)
					{
						if (a[y][j] == ch)r[y][j] = true;
						else break;
					}
				}
				
			}
		}
	}
	bool ok = false;
	FOR(i, 40)
	{
		FOR(j, 40)
		{
			if (r[i][j])
			{
				a[i][j] = '.';
				ok = true;
			}
		}
	}
	return ok;
}

void fall(P &a)
{
	bool ok = true;
	while (ok)
	{
		ok = false;
		FORI(i,2,h+1)
		{
			FORI(j, 1, w + 1)
			{
				if (a[i][j] == '.'&&a[i - 1][j] != '.')
				{
					swap(a[i][j], a[i - 1][j]);
					ok = true;
				}
			}
		}
	}
}

int main()
{

	cin >> h >> w >> n;
	
	vc wall(40, '!');
	P a(40,wall);

	FORI(i, 1, h+1)
	{
		FORI(j, 1, w + 1)
		{
			cin >> a[i][j];
		}
	}

	FORI(i, 1, h + 1)
	{
		FORI(j, 1, w)
		{
			if (a[i][j] != a[i][j + 1])
			{
				P x = a;
				swap(x[i][j], x[i][j + 1]);
				fall(x);
				while (remove(x))
				{
					fall(x);
				}

				if (check(x))
				{
					cout << "YES" << endl;
					return 0;
				}
			}
		}
	}

	cout << "NO" << endl;

}