giúp tớ với tớ cảm ơn

program bai_giai;
uses crt;
var k,n,a,b,c:integer;
procedure k1;
var kq:integer;
begin
    kq:=n-(n-a)-(n-b)-(n-c);
    if kq<0 then kq:=0;
    write(kq);
end;
procedure k2;
var kq:integer;
begin
    kq:=a;
    if b<kq then kq:=b;
    if c<kq then kq:=c;
    write(kq);
end;
BEGIN
    clrscr;
    readln(k);
    read(n,a,b,c);
    if k=1 then k1 else k2;
    readln;  readln;
END.