#include<bits/stdc++.h>

using namespace std;

int find(vector<vector<int>>&mat)

{

int n=mat.size();

int m=mat[0].size();

vector<pair<int,int>>d={{-1,0},{1,0},{0,-1},{0,1}};

queue<pair<int,int>>q;

for(int i=0;i<n;i++)

{

for(int j=0;j<m;j++)

{

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

{

q.push({i,j});

mat[i][j]=1;

}

}

}

int level=0;

while(!q.empty())

{

int size=q.size();

for(int i=0;i<size;i++)

{

auto temp=q.front();

q.pop();

int x=temp.first;

int y=temp.second;

if(x==0||y==0||x==n-1||y==m-1)

{

return level;

}

for(auto it:d)

{

int nx=x+it.first;

int ny=y+it.second;

if(nx>=0&&ny>=0&&nx<n&&ny<m&&mat[nx][ny]==0)

{

mat[nx][ny]=1;

q.push({nx,ny});

}

}

}

level++;

}

return -1;

}

int main()

{

int n,m;

cin>>n>>m;

vector<vector<int>>mat(n,vector<int>(m));

for(int i=0;i<n;i++)

{

for(int j=0;j<m;j++)

{

cin>>mat[i][j];

}

}

cout<<find(mat)<<endl;

}

#include <iostream>
#include <unordered_map>
#include <string>
using namespace std;
int main() {
    int n;
    cin >> n;  
    string str;
    cin >> str;  
    unordered_map<char, int> v;
    v['a'] = 0;
    v['e'] = 0;
    v['i'] = 0;
    v['o'] = 0;
    v['u'] = 0;
        for (char c : str) {
        if (v.find(c) != v.end()) {
            v[c]++;
        }
    }
    char m = 'a';
    int e = v['a'];
    for (auto &pair : v) {
        if (pair.second > e) {
            m = pair.first;
            e = pair.second;
        }
    }
        cout << m << endl;
    
    return 0;
}

#include <iostream>
#include <string>
using namespace std;
const int MOD = 1000000007;
int main() {
    int n;
    cin >> n; 
    string s;
    cin >> s;  
        if (n == 1) {
        cout << 2 << endl;
        return 0;
    }
        int a = 0;
        for (int i = 0; i < n; i++) {
        for (int j = i; j < n; j++) {
            string r = s.substr(0, i) + s.substr(j + 1);
            if (r.empty() || r.find_first_not_of(r[0]) == string::npos) 
            {
                a++;
            }
        }
    }
        cout << a % MOD << endl;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;
#define int long long
using namespace std;
int solution(vector<int> &A) {
    int n = A.size();
    int m = 0;
    int i = 0;
    while (i < n - 1) {
        if (A[i] >= A[i + 1]) {
            int j = i + 1;
            while (j < n && A[j] <= A[j - 1]) {
                j++;
            }
                        m++;
                        i = j;
        } else {
            i++;
        }
    }
    
    return m;
}

SELECT 
    c.mac,
    SUM(t.amount) AS traffic,
    ROUND(SUM(t.amount) * c.tariff, 2) AS cost
FROM 
    clients c
JOIN 
    traffic t ON c.id = t.client_id
WHERE 
    t.dt LIKE '2022-05%'
GROUP BY 
    c.mac, c.tariff
ORDER BY 
    cost DESC;

def largest_x(matrix):
    R, C = len(matrix), len(matrix[0])
    lu = [[0]*C for _ in range(R)]
    ru = [[0]*C for _ in range(R)]
    ld = [[0]*C for _ in range(R)]
    rd = [[0]*C for _ in range(R)]
    
    for r in range(R):
        for c in range(C):
            if matrix[r][c]:
                lu[r][c] = 1 + (lu[r-1][c-1] if r and c else 0)
                ru[r][c] = 1 + (ru[r-1][c+1] if r and c < C-1 else 0)
                
    for r in range(R-1, -1, -1):
        for c in range(C):
            if matrix[r][c]:
                ld[r][c] = 1 + (ld[r+1][c-1] if r < R-1 and c else 0)
                rd[r][c] = 1 + (rd[r+1][c+1] if r < R-1 and c < C-1 else 0)
    
    max_size, res = 0, [0,0]
    for r in range(R):
        for c in range(C):
            if matrix[r][c]:
                s = min(lu[r][c], ru[r][c], ld[r][c], rd[r][c])
                if s > max_size or (s == max_size and (r < res[0] or (r == res[0] and c < res[1]))):
                    max_size, res = s, [r, c]
    return res