#include <algorithm>
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(x) (x).begin(), (x).end()
#define ll long long
#define ld long double
#define INF 1000000000000000000
typedef pair<ll, ll> pll;
typedef pair<int, int> pint;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int H, W;
    cin >> H >> W;
    vector<vector<char>> G(H, vector<char>(W));
    rep(i, H) {
        rep(j, W) { cin >> G[i][j]; }
    }

    vector<vector<ll>> dp(H, vector<ll>(W, INF));

    int dx[4] = {1, 0, -1, 0};
    int dy[4] = {0, 1, 0, -1};
    dp[0][0] = 0;
    rep(i, H) {
        rep(j, W) {
            if (i == 0 && j == 0)
                continue;
            if (G[i][j] == '.') {
                ll tmp1 = (i - 1 >= 0) ? dp[i - 1][j] : INF;
                ll tmp2 = (j - 1 >= 0) ? dp[i][j - 1] : INF;
                dp[i][j] = min(tmp1, tmp2) + 1;
            } else {
                ll tmp1 = (i - 1 >= 0) ? dp[i - 1][j] : INF;
                ll tmp2 = (j - 1 >= 0) ? dp[i][j - 1] : INF;
                dp[i][j] = min(tmp1, tmp2) + 1 + i + j;
            }
        }
    }

    cout << dp[H - 1][W - 1] << endl;
}