#ifdef LOCAL111 #else #define NDEBUG #endif #include const int INF = 1e9; using namespace std; template ostream& operator<< (ostream& os, const pair& p) { cout << '(' << p.first << ' ' << p.second << ')'; return os; } #define endl '\n' #define ALL(a) (a).begin(),(a).end() #define SZ(a) int((a).size()) #define FOR(i,a,b) for(int i=(a);i<(b);++i) #define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--) #define REP(i,n) FOR(i,0,n) #define RREP(i,n) for (int i=(n)-1;i>=0;i--) #define RBP(i,a) for(auto& i : a) #ifdef LOCAL111 #define DEBUG(x) cout<<#x<<": "<<(x)< void dpite(T a, T b){ for(T ite = a; ite != b; ite++) cout << (ite == a ? "" : " ") << *ite; cout << endl;} #else #define DEBUG(x) true template void dpite(T a, T b){ return; } #endif #define F first #define S second #define SNP string::npos #define WRC(hoge) cout << "Case #" << (hoge)+1 << ": " #define rangej(a,b,c) ((a) <= (c) and (c) < (b)) #define rrangej(b,c) rangej(0,b,c) template void pite(T a, T b){ for(T ite = a; ite != b; ite++) cout << (ite == a ? "" : " ") << *ite; cout << endl;} template bool chmax(T& a, T b){if(a < b){a = b; return true;} return false;} template bool chmin(T& a, T b){if(a > b){a = b; return true;} return false;} typedef long long int LL; typedef unsigned long long ULL; typedef pair P; typedef pair LP; void ios_init(){ //cout.setf(ios::fixed); //cout.precision(12); #ifdef LOCAL111 return; #endif ios::sync_with_stdio(false); cin.tie(0); } const string yuki = "yuki"; int main() { ios_init(); int n; while(cin >> n) { string s; cin >> s; sort(ALL(s)); int ans = 0; int cy = 0; DEBUG(s); REP(p,SZ(yuki)){ if(p == 0){ RREP(i,SZ(s)){ if(s[i] > yuki[p]){ ans++; s.pop_back(); }else if(s[i] == yuki[p]){ s.pop_back(); cy++; }else{ break; } } }else{ int cnt = 0; RREP(i,SZ(s)){ if(s[i] > yuki[p] and cy != 0){ ans++; cy--; s.pop_back(); }else if(s[i] == yuki[p] and cnt < cy){ cnt++; s.pop_back(); }else{ break; } } if(cnt < cy){ ans += (cy-cnt)/2; } cy = cnt; } DEBUG(cy); } ans += min(SZ(s),cy); cout << ans << endl; } return 0; }