def main():
    s = input()
    ans = 1000

    for i in range(len(s)):
        if s[i] == 'c':
            n = 0
            for j in range(i, len(s)):
                if s[j] == 'w':
                    n += 1
                if n == 2:
                    ans = min(ans, j - i + 1)
                    break

    print(ans if ans != 1000 else -1)

if __name__ == '__main__':
    main()