#include <iostream>

#include <vector>

#include <queue>

#include <cstring>

using namespace std;

int N,M;

int map[51][51] = {0,};

vector<pair<int, int> > virus;

int check[11] = {0,};

int dy[4] = {-1,1,0,0};

int dx[4] = {0,0,-1,1};

int min_sec = 987654321;

int Empty = 0;

int go(){

queue<pair<int,int> > q;

int sec[51][51];

memset(sec, -1, sizeof(sec));

int size = virus.size();

for(int k=0; k<size; k++){

if(check[k]){

q.push(make_pair(virus[k].first, virus[k].second));

sec[virus[k].first][virus[k].second] = 0;

}

}

int infect = 0;

int total_time = 0;

while(!q.empty()){

int y = q.front().first;

int x = q.front().second;

q.pop();

for(int i=0; i<4; i++){

int ny = y + dy[i];

int nx = x + dx[i];

if((ny<0) || (nx<0) || (ny>=N) || (nx>=N))

continue;

if((map[ny][nx] == 0) && sec[ny][nx]==-1){

sec[ny][nx] = sec[y][x] + 1;

q.push(make_pair(ny, nx));

infect++;

total_time = sec[ny][nx];

}

if((map[ny][nx] == 2) && sec[ny][nx]==-1){

sec[ny][nx] = sec[y][x] + 1;

q.push(make_pair(ny, nx));

}

}

}

if(Empty == infect)

return total_time;

return min_sec;

}

void dfs(int idx, int cnt){

if(cnt == M){

int sec = go();

min_sec = min(min_sec, sec);

return;

}

int size = virus.size();

for(int i=idx+1; i<size; i++){

check[i] = 1;

dfs(i, cnt+1);

check[i] = 0;

}

}

int main(int argc, char const *argv[])

{

ios::sync_with_stdio(false);

cin.tie(0);

cin>>N>>M;

for(int i=0; i<N; i++){

for(int j=0; j<N; j++){

cin>>map[i][j];

if(map[i][j] == 0)

Empty++;

if(map[i][j] == 2)

virus.push_back(make_pair(i, j));

}

}

dfs(-1, 0);

if(min_sec == 987654321)

cout<<"-1\n";

else

cout<<min_sec<<"\n";

return 0;

}