def solve():
    S = input()
    L = len(S)

    ans = 114514
    for i, c in enumerate(S):
        if c == 'c':
            nw = 0
            for j in range(i + 1, L):
                w = S[j]
                if w == 'w':
                    nw += 1
                    if nw >= 2:
                        ans = min(ans, j - i + 1)
    if ans == 114514:
        print(-1)
    else:
        print(ans)


if __name__ == '__main__':
    solve()