1
n, m = map(int, input().split())
2
table = []
3
for i in range(n):
4
    row = input()
5
    table.append(row)
6
    
7
row = [False for i in range(n)]
8
col = [False for j in range(m)]
9
 
10
for i in range(n):
11
    for j in range(m):
12
        if table[i][j] == 'S':
13
            row[i] = col[j] = True
14
            
15
used = [[False for j in range(m)] for i in range(n)]
16
 
17
ans = 0
18
 
19
for i in range(n):
20
    if row[i] == False:
21
        for j in range(m):
22
            if used[i][j] == False:
23
                ans += 1
24
                used[i][j] = True
25
 
26
for j in range(m):
27
    if col[j] == False:
28
        for i in range(n):
29
            if used[i][j] == False:
30
                ans += 1
31
                used[i][j] = True
32
                
33
print(ans)
34
 
35