#include <cstdio>
#include <iostream>
#include <vector>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <algorithm>

using namespace std;

#define DEBUG  //comment this line to pull out print statements
#ifdef DEBUG
#define TAB '\t'
#define debug(a, end) cout << #a << ": " << a << end
#define dbg(end) end
#else
#define debug(a, end)
#define dbg(end)
#endif

typedef pair<int, int> point;
typedef vector<int> vi;
typedef vector<point> vp;

#define UN(v) SORT(v),v.erase(unique(v.begin(),v.end()),v.end())   
#define SORT(c) sort((c).begin(),(c).end())   
#define FOR(i,a,b) for (int  i=(a); i < (b); i++)    
#define REP(i,n) FOR(i,0,(int)n)    
#define CL(a,b) memset(a,b,sizeof(a))
#define CL2d(a,b,x,y) memset(a, b, sizeof(a[0][0])*x*y)

/*global variables*/
char board[9][9];
const int offset = 2;
/*global variables*/

void dump()
{
    //dump data
}

bool getInput()
{
    //get input
    REP(i, 5)
    {
        REP(j, 5)
        {
            scanf("%c", &board[offset+i][offset+j]);
        }
        scanf(" ");
    }
    return true;
}

bool check_knight(int row, int col)
{
    return (
        //top left
        (board[row+offset-2][col+offset-1] == '.') &&
    
        //top right
        (board[row+offset-2][col+offset+1] == '.') &&
    
        //left up
        (board[row+offset-1][col+offset-2] == '.') &&
    
        //left down
        (board[row+offset+1][col+offset-2] == '.') &&

        //bot left
        (board[row+offset+2][col+offset-1] == '.') &&

        //bot right
        (board[row+offset+2][col+offset+1] == '.') &&

        //right up
        (board[row+offset-1][col+offset+2] == '.') &&

        //right down
        (board[row+offset+1][col+offset+2] == '.'));
}

void process()
{
    //process input
    bool v = true;

    //count knights as well.
    int nk = 0;
    REP(i, 5)
    {
        REP(j, 5)
        {
            if (board[offset+i][offset+j] == 'k')
            {
                if (v) v = check_knight(i, j);
                nk++;
            }
        }
    }

    printf("%svalid\n", nk == 9 ? (v ? "" : "in") : "in");
}

int main()
{
        /*CLEAR GLOBAL VARIABLES!*/
        CL2d(board, '.', 9, 9);
        /*CLEAR GLOBAL VARIABLES!*/
        
        getInput();
        process();

    return 0;
}