dc:array[1..1000]of integer;

i,j,m,n,t,tm,f:integer;

begin

readln(m,n);

for i:=1 to n do

read(dc[i]);

readln;

t:=0;

f:=0;

tm:=1;

for i:=1 to m do

nc[i]:=0;

for i:=1 to n do

begin

for j:=1 to m do

if dc[i]=nc[j] then f:=1;

if f=0 then

begin

nc[tm]:=dc[i];

t:=t+1;

tm:=tm+1;

if tm=m+1 then tm:=1;

end;

end;

writeln(t);

end.