#include<cstdio>
#include<iostream>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<iomanip>
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
using namespace std;

const int N=55,inf=1e9;
int n,m;
int a[N][N]; 
double dp[N][N];

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0),cout.tie(0);
	cin>>n>>m;
	rep(i,0,n-1) rep(j,0,m-1) {
		char x;cin>>x;
		if(x=='#') a[i][j]=1;
	}
	
	rep(i,0,n) rep(j,0,m) dp[i][j]=inf;
	dp[0][0]=0;
	
	rep(i,0,n) rep(j,0,m) {
		if(i>0) dp[i][j]=min(dp[i][j],dp[i-1][j]+1);
		if(j>0) dp[i][j]=min(dp[i][j],dp[i][j-1]+1);
		rep(x,0,i-1) rep(y,0,j-1) {
			bool ok=1;
			rep(l,x,i-1) rep(r,y,j-1) {
				if((r-y)*(i-x)<(l-x+1)*(j-y) && (l-x)*(j-y)<(r-y+1)*(i-x) && a[l][r]) {
					ok=0;
					break;
				}
				if(!ok) break;
			}
			if(ok) dp[i][j]=min(dp[i][j],dp[x][y]+sqrt((i-x)*(i-x)+(j-y)*(j-y)));
		}
	}
	
	cout<<fixed<<setprecision(8)<<dp[n][m]<<'\n';

	return 0;
}
/*
4 4
..#.
.#.#
###.
.#..
*/