S = input().strip()

min_length = float('inf')

# Find all positions of 'c'
c_positions = [i for i, char in enumerate(S) if char == 'c']

for i in c_positions:
    # Find the first 'w' after position i
    j = -1
    for idx in range(i + 1, len(S)):
        if S[idx] == 'w':
            j = idx
            break
    if j == -1:
        continue  # No first 'w' found
    
    # Find the second 'w' after position j
    k = -1
    for idx in range(j + 1, len(S)):
        if S[idx] == 'w':
            k = idx
            break
    if k == -1:
        continue  # No second 'w' found
    
    # Calculate the length of the substring
    current_length = k - i + 1
    if current_length < min_length:
        min_length = current_length

print(min_length if min_length != float('inf') else -1)