#include <bits/stdc++.h>
using namespace std;

typedef long long   signed int LL;
typedef long long unsigned int LU;

#define incID(i, l, r) for(int i = (l)    ; i <  (r); i++)
#define incII(i, l, r) for(int i = (l)    ; i <= (r); i++)
#define decID(i, l, r) for(int i = (r) - 1; i >= (l); i--)
#define decII(i, l, r) for(int i = (r)    ; i >= (l); i--)
#define  inc(i, n) incID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define  dec(i, n) decID(i, 0, n)
#define dec1(i, n) decII(i, 1, n)

#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define inID(v, l, r) ((l) <= (v) && (v) <  (r))

#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define UB upper_bound
#define LB lower_bound
#define PQ priority_queue

#define  ALL(v)  v.begin(),  v.end()
#define RALL(v) v.rbegin(), v.rend()
#define  FOR(it, v) for(auto it =  v.begin(); it !=  v.end(); ++it)
#define RFOR(it, v) for(auto it = v.rbegin(); it != v.rend(); ++it)

template<typename T> bool   setmin(T & a, T b) { if(b <  a) { a = b; return true; } else { return false; } }
template<typename T> bool   setmax(T & a, T b) { if(b >  a) { a = b; return true; } else { return false; } }
template<typename T> bool setmineq(T & a, T b) { if(b <= a) { a = b; return true; } else { return false; } }
template<typename T> bool setmaxeq(T & a, T b) { if(b >= a) { a = b; return true; } else { return false; } }
template<typename T> T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

// ---- ----

string s;
set<array<int, 6>> sa, sa2;

int main() {
	cin >> s;
	
	int n = s.size();
	sa.insert({ n / 5, 0, 0, 0, 0, 0 });
	inc(i, s.size()) {
		int p = -1;
		inc(j, 6) { if(s[i] == ("KUROI?"[j])) { p = j; } }
		if(p == -1) { continue; }
		inc(j, 5) {
			if(p == j || p == 5) {
				FOR(it, sa) {
					auto x = (*it);
					if(x[j] > 0) { x[j]--; x[j + 1]++; if(p == 5) { sa2.insert(x); } }
					if(p != 5) { sa2.insert(x); }
				}
			}
		}
		
		// FOR(it, sa2) { sa.insert(*it); }
		swap(sa, sa2);
		sa2.clear();
		// cout << i << ": " << sa.size() << endl;
	}
	
	int ans = 0;
	FOR(it, sa) { setmax(ans, (*it)[5]); }
	
	cout << ans << endl;
	
	return 0;
}