def main():
   
    s = input()
    length_minimom = float('inf')

    for c in range(len(s)):
        if s[c] == 'c':
            count_cww = 0
            for w in range(c+1, len(s)):
                if s[w] == 'w':
                    count_cww += 1
                    if count_cww == 2:
                        length_minimom = min(length_minimom, w - c + 1)
                        break
                    
    if length_minimom == float('inf'):
        print(-1)
    else:
        print(length_minimom)
    
if __name__ == '__main__':
    main()