#include <bits/stdc++.h>
using namespace std;

using i64 = long long;

int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    
    auto solve = [&]() {
        int n, m;
        cin >> n >> m;

        vector<string> a(n);
        for (int i = 0; i < n; i++) {
            cin >> a[i];
        }

        vector dp(n, vector<int>(m));

        for (int i = 0; i < n; i++) {
            for (int j = m - 1; j >= 0; j--) {
                if (i == 0 && j == m - 1) {
                    dp[i][j] = a[i][j] == 'C';
                    continue;
                } 
                if (i > 0 && j + 1 < m) {
                    dp[i][j] = max(dp[i][j], dp[i - 1][j + 1] + (a[i][j] == 'C'));
                }
                if (i > 0) {
                    dp[i][j] = max(dp[i][j], dp[i - 1][j]);
                }
                if (j + 1 < m) {
                    dp[i][j] = max(dp[i][j], dp[i][j + 1]);
                }
            }
        }

        cout << dp[n - 1][0] << '\n';
    };

    solve();

    return 0;
}