2178.cpp

// Authored by : BaaaaaaaaaaarkingDog
// Co-authored by : -
// http://boj.kr/cd14bec9ecff461ab840f853ed0eb87f
#include <bits/stdc++.h>
using namespace std;
#define X first
#define Y second
string board[102];
int dist[102][102];
int n,m;
int dx[4] = {1,0,-1,0};
int dy[4] = {0,1,0,-1};
int main(void){
  ios::sync_with_stdio(0);
  cin.tie(0);
  cin >> n >> m;
  for(int i = 0; i < n; i++)
    cin >> board[i];
  for(int i = 0; i < n; i++) fill(dist[i],dist[i]+m,-1);
  queue<pair<int,int> > Q;
  Q.push({0,0});
  dist[0][0] = 0;
  while(!Q.empty()){
    auto cur = Q.front(); Q.pop();
    for(int dir = 0; dir < 4; dir++){
      int nx = cur.X + dx[dir];
      int ny = cur.Y + dy[dir];
      if(nx < 0 || nx >= n || ny < 0 || ny >= m) continue;
      if(dist[nx][ny] >= 0 || board[nx][ny] != '1') continue;
      dist[nx][ny] = dist[cur.X][cur.Y]+1;
      Q.push({nx,ny});
    }
  }
  cout << dist[n-1][m-1]+1; // 문제의 특성상 거리+1이 정답
}