import sys
def f(x1,y1,x2,y2):
if x1 == x2 or y1 == y2 or abs(x1-x2) == abs(y1-y2):
return True
return False
L = []
Queen = []
for i in range(8):
L.append(input())
for y in range(8):
for x in range(8):
if L[y][x] == '*':
Queen.append([y,x])
if len(Queen) !=8:
print("invalid")
sys.exit()
for i in range(len(Queen)):
for j in range(i+1,len(Queen)):
if f(Queen[i][0],Queen[i][1],Queen[j][0],Queen[j][1]):
print("invalid")
sys.exit()
print("valid")