import sys
input = lambda:sys.stdin.readline().strip()
n,m = map(int, input().split())
MD=998244353
s1 = [[0] * (m+1) for _ in range(n+1)]
s2 = [[0] * (m+1) for _ in range(n+1)]
s3 = [[0] * (m+1) for _ in range(n+1)]
def acc(x, y):
    for m in [s1,s2,s3]:
        m[x+1][y+1] = m[x][y+1] + m[x+1][y] - m[x][y]
        m[x+1][y+1] %= MD
for i in range(n):
    inp = input()
    for j in range(m):
        acc(i, j)
        if inp[j] == 'R':
            s1[i+1][j+1] += 1
        elif inp[j] == 'O':
            s2[i+1][j+1] += s1[i+1][j+1]
        elif inp[j] == 'G':
            s3[i+1][j+1] += s2[i+1][j+1]
print(s3[n][m]%MD)