import collections

target = 'KUROI'
S = input()

def solve(S):
    lst = preprocess(S)
    m = len(lst) // len(target)
    dp = collections.defaultdict(int)
    dp[0,0,0,0] = 0
    for c in lst:
        update_dp(dp, c)
    return max(dp.values())


def preprocess(S):
    candidates = target + '?'
    dic = {c: i for i, c in enumerate(candidates)}
    return [dic[c] for c in S if c in dic]


def update_dp(dp, c):
    if c == 0:
        update_dp0(dp)
    elif c == 1:
        update_dp1(dp)
    elif c == 2:
        update_dp2(dp)
    elif c == 3:
        update_dp3(dp)
    elif c == 4:
        update_dp4(dp)
    else:
        update_dp5(dp)


def update_dp5(dp):
    for (k0, k1, k2, k3), val in list(dp.items()):
        if k3 > val:
            dp[k0, k1, k2, k3] += 1
        if k2 > k3:
            new_key = (k0, k1, k2, k3 + 1)
            if (new_key not in dp) or dp[new_key] < val:
                dp[new_key] = val
        if k1 > k2:
            new_key = (k0, k1, k2 + 1, k3)
            if (new_key not in dp) or dp[new_key] < val:
                dp[new_key] = val
        if k0 > k1:
            new_key = (k0, k1 + 1, k2, k3)
            if (new_key not in dp) or dp[new_key] < val:
                dp[new_key] = val
        if 20 > k0:
            new_key = (k0 + 1, k1, k2, k3)
            if (new_key not in dp) or dp[new_key] < val:
                dp[new_key] = val
            

def update_dp4(dp):
    for (k0, k1, k2, k3), val in list(dp.items()):
        if k3 > val:
            dp[k0, k1, k2, k3] += 1

def update_dp3(dp):
    for (k0, k1, k2, k3), val in list(dp.items()):
        if k2 > k3:
            new_key = (k0, k1, k2, k3 + 1)
            if (new_key not in dp) or dp[new_key] < val:
                dp[new_key] = val

def update_dp2(dp):
    for (k0, k1, k2, k3), val in list(dp.items()):
        if k1 > k2:
            new_key = (k0, k1, k2 + 1, k3)
            if (new_key not in dp) or dp[new_key] < val:
                dp[new_key] = val

def update_dp1(dp):
    for (k0, k1, k2, k3), val in list(dp.items()):
        if k0 > k1:
            new_key = (k0, k1+1, k2, k3)
            if (new_key not in dp) or dp[new_key] < val:
                dp[new_key] = val

def update_dp0(dp):
    for (k0, k1, k2, k3), val in list(dp.items()):
        if 20 > k0:
            new_key = (k0+1, k1, k2, k3)
            if (new_key not in dp) or dp[new_key] < val:
                dp[new_key] = val

print(solve(S))