def main(S: str) -> int:
    n = len(S)
    min_length = float('inf')
    found = False

    for i in range(n):
        if S[i] == 'c':
            first_w = -1
            second_w = -1
            for j in range(i + 1, n):
                if S[j] == 'w':
                    if first_w == -1:
                        first_w = j
                    elif second_w == -1:
                        second_w = j
                        min_length = min(min_length, second_w - i + 1)
                        found = True
                        break

    print(min_length if found else -1)

if __name__ == "__main__":
    S = input().strip()
    main(S)