s = input().strip()
# dp represents the counts for each stage: K, KU, KUR, KURO, KUROI
dp = [0, 0, 0, 0, 0]

for c in s:
    # Determine possible characters for the current position
    if c == '?':
        candidates = ['K', 'U', 'R', 'O', 'I']
    else:
        candidates = [c]
    
    new_dp = list(dp)
    for char in candidates:
        current = list(dp)
        if char == 'K':
            current[0] += 1
        elif char == 'U':
            if current[0] > current[1]:
                current[1] += 1
        elif char == 'R':
            if current[1] > current[2]:
                current[2] += 1
        elif char == 'O':
            if current[2] > current[3]:
                current[3] += 1
        elif char == 'I':
            if current[3] > current[4]:
                current[4] += 1
        # Update new_dp to keep the maximum values for each stage
        for i in range(5):
            if current[i] > new_dp[i]:
                new_dp[i] = current[i]
    dp = new_dp

print(dp[4])