#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<bitset>
#include<set>
#include<map>
#include<stack>
#include<queue>
#include<deque>
#include<list>
#include<iomanip>
#include<cmath>
#include<cstring>
#include<functional>
using namespace std;

#define repr(i, a, b) for (int i = (int)(a); i < (int)(b); i++)
#define rep(i, n) repr(i, 0, n)
#define INF 2e9
#define MOD 1000000007
//#define MOD 998244353
#define LINF (long long)4e18
#define jck 3.141592

using ll = long long;
using Pi = pair<int,int>;
using Pl = pair<ll,ll>;

ll dp[2020][2020];

int main(){
    int H,W; cin >> H >> W;
    vector<string> a(H);
    rep(i,H) cin >> a[i];
    rep(i,2020)rep(j,2020) dp[i][j] = LINF;
    dp[0][0] = 0;
    rep(i,H)rep(j,W){
        if(i+1 < H){
            if(a[i+1][j] == '.') dp[i+1][j] = min(dp[i+1][j],dp[i][j]+1);
            else dp[i+1][j] = min(dp[i+1][j],dp[i][j]+i+j+2);
        }
        if(j+1 < W){
            if(a[i][j+1] == '.') dp[i][j+1] = min(dp[i][j+1],dp[i][j]+1);
            else dp[i][j+1] = min(dp[i][j+1],dp[i][j]+i+j+2);
        }
    }
    //rep(i,H)rep(j,W) cout << dp[i][j] << endl;
    cout << dp[H-1][W-1] << endl;
}