import sys

# S = input()
S = "wachiwachi"

cpos = [i for i, x in enumerate(S) if x == "c"]

wpos = [i for i, x in enumerate(S) if x == "w"]

ans = -1

if len(cpos) == 0 or len(wpos) <= 1:
    print(-1)
    sys.exit()

for i in cpos:
    wpostemp = [j for j in wpos if j > i]
    if len(wpostemp) <= 1:
        break

    if ans < wpostemp[1] - i + 1:
        ans = wpostemp[1] - i + 1

print(ans)