#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0;i < n;i++)
template<class T> bool chmin(T &a,T b){
    if(a>b){a = b;return true;}
    return false;
}
template<class T> bool chmax(T &a,T b){
    if(a<b){a = b;return true;}
    return false;
}

using ll = long long;
using ld = long double;

const int INF = 1e9+5;
// const int mod = 1000000007;
const int mod = 998244353;

void no(){
    cout << "No" << endl;exit(0);
}
void yes(){
    cout << "Yes" << endl; exit(0);
}
#define all(x) x.begin(),x.end()
vector dx = {0,1},dy = {1,0};

int main(){
    int H,W;cin >> H >> W;
    vector<string>A(H);
    rep(i,H)cin >> A[i];
    //→H個↓W個の並び替え
    int res = 0;
    auto dfs = [&](auto &dfs,int i,int j,int now){
        if(i==H-1&&j==W-1&&now>=0){res++;return;}
        rep(d,2){
            int ni = i+dx[d],nj = j+dy[d];
            if(ni>=H||nj>=W)continue;
            if(A[ni][nj]=='#')continue;
            if(now==0&&A[ni][nj]=='x')continue;
            dfs(dfs,ni,nj,(A[ni][nj]=='x'?now-1:now+1));
        }
    };
    dfs(dfs,0,0,1);
    cout << res << endl;



}