#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

#define rd_init() char*rp=({char*mmap();mmap(0l,1l<<25,1,2,0,0ll);})
#define rd() ({long _v=0,_c;while(_c=*rp++-48,_c>=0)_v=_v*10+_c;_v;})
#define wt(v) ({ulong _z=v;do*--wp=_z%10+48;while(_z/=10);})
#define wt1(v) ({char wbuf[64],*wp=wbuf+sizeof wbuf;wt(v);write(1,wp,wbuf+sizeof wbuf-wp);})
#define rep(v,e) for(typeof(e) v=0;v<e;++v)

typedef unsigned long ulong;

int b[100004];
int c[100004];

int main(){
	rd_init();
	int n=rd();
	int k=rd();
	rep(i,n){
		int a=rd();
		b[a]+=1;
	}
	rep(i,100004){
		c[b[i]]+=1;
	}
	int i=100004;
	int z=0;
	while(k>0){
		while(!c[i]){
			i-=1;
		}
		int x=c[i];
		while(k>0&&x){
			k-=i;
			x-=1;
			z+=1;
		}
		i-=1;
	}
	wt1(z);
	_exit(0);
}