#include "bits/stdc++.h" using namespace std; typedef long long ll; typedef pair pii; typedef pair pll; const int INF = 1e9; const ll LINF = 1e18; template ostream& operator << (ostream& out,const pair& o){ out << "(" << o.first << "," << o.second << ")"; return out; } template ostream& operator << (ostream& out,const vector V){ for(int i = 0; i < V.size(); i++){ out << V[i]; if(i!=V.size()-1) out << " ";} return out; } template ostream& operator << (ostream& out,const vector > Mat){ for(int i = 0; i < Mat.size(); i++) { if(i != 0) out << endl; out << Mat[i];} return out; } template ostream& operator << (ostream& out,const map mp){ out << "{ "; for(auto it = mp.begin(); it != mp.end(); it++){ out << it->first << ":" << it->second; if(mp.size()-1 != distance(mp.begin(),it)) out << ", "; } out << " }"; return out; } /* 問題文============================================================ ================================================================= 解説============================================================= ================================================================ */ ll dp[110][21][21][21][21]; ll solve(){ ll res = 0; string S; cin >> S; int L = (int)S.length(); fill(****dp,****dp+2*21*21*21*21,-1); int cur = 0,next = 1; dp[cur][0][0][0][0] = 0; for(int _ = 0; _ < L;_++){ cur = _; next = cur + 1; for(int k = 0; k < 21;k++){ for(int u = 0; u < 21;u++){ for(int r = 0; r < 21;r++){ for(int o = 0; o < 21;o++){ if(dp[cur][k][u][r][o]==-1)continue; ll i = dp[cur][k][u][r][o]; if(S[_]=='K'||S[_]=='?') if(k<20) dp[next][k+1][u][r][o]=max(dp[next][k+1][u][r][o],i); if(S[_]=='U'||S[_]=='?') if(u<20&&k) dp[next][k-1][u+1][r][o]=max(dp[next][k-1][u+1][r][o],i); if(S[_]=='R'||S[_]=='?') if(r<20&&u) dp[next][k][u-1][r+1][o]=max(dp[next][k][u-1][r+1][o],i); if(S[_]=='O'||S[_]=='?') if(o<20&&r) dp[next][k][u][r-1][o+1]=max(dp[next][k][u][r-1][o+1],i); if(S[_]=='I'||S[_]=='?') if(o){ res = max(res,i+1); dp[next][k][u][r][o-1]=max(dp[next][k][u][r][o-1],i+1); } } } } } } return res; } int main(void) { cin.tie(0); ios_base::sync_with_stdio(false); cout << solve() << endl; return 0; }