#include <iostream>

#include <list>

using namespace std;

list<int> bfsQueueX;

list<int> bfsQueueY;

int N, M;

int board[101][101];

bool visited[101][101];

void bfs() {

if (bfsQueueX.empty()) return;

int x = bfsQueueX.front();

int y = bfsQueueY.front();

bfsQueueX.pop_front(); bfsQueueY.pop_front();

int level = board[x][y];

if (x > 0 && board[x - 1][y] == 1 && !visited[x - 1][y]) {

visited[x - 1][y] = true;

board[x - 1][y] = level + 1;

bfsQueueX.push_back(x - 1); bfsQueueY.push_back(y);

}

if (y > 0 && board[x][y - 1] == 1 && !visited[x][y - 1]) {

visited[x][y - 1] = true;

board[x][y - 1] = level + 1;

bfsQueueX.push_back(x); bfsQueueY.push_back(y - 1);

}

if (x < N - 1 && board[x + 1][y] == 1 && !visited[x + 1][y]) {

visited[x + 1][y] = true;

board[x + 1][y] = level + 1;

bfsQueueX.push_back(x + 1); bfsQueueY.push_back(y);

}

if (y < M - 1 && board[x][y + 1] == 1 && !visited[x][y + 1]) {

visited[x][y + 1] = true;

board[x][y + 1] = level + 1;

bfsQueueX.push_back(x); bfsQueueY.push_back(y + 1);

}

bfs();

}

int main()

{

int i, j;

cin >> N >> M;

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

string tmp;

cin >> tmp;

for (j = 0; j < M; j++) {

visited[i][j] = false;

if (tmp[j] == '0') board[i][j] = 0;

else board[i][j] = 1;

}

}

bfsQueueX.push_back(0);

bfsQueueY.push_back(0);

visited[0][0] = true;

bfs();

cout << board[N - 1][M - 1];

}