#include //#include //using namespace atcoder; using namespace std; const int INF = 1e9; using ll = long long; using ull = unsigned long long; using inv = vector; using stv = vector; using pint = pair; #define FOR(i,l,r) for(int i=(l); i<(r); i++) #define rep(i,r) for(int i=0; i<(r); i++) #define repl(i,r) for(long long i=0; i<(r); i++) #define FORl(i,l,r) for(long long i=(l); i<(r); i++) #define INFL ((1LL<<62)-(1LL<<31)) #define pb(x) push_back(x) int main(){ int N,K; cin >> N >> K; inv C(N,0); inv A(N); rep(i,N) cin >> A[i]; rep(i,N) C[A[i]]++; sort(C.begin(),C.end(),greater()); int ans = 0; rep(i,N){ K -= C[i]; ans++; if(K <= 0){ break; } } cout << ans << endl; return 0; }