uses crt;
var i,n,k:integer; a:array[1..1000000]of string; s:string;
begin
clrscr;
write('Nhap so luong hoc sinh: ');readln(n);
for i:=1 to n do
begin
write('Nhap ten cua ban thu ',i,': ');readln(a[i]);
end;
write('Nhap mot ten: ');readln(s);
for i:=1 to n do if a[i]=s then k:=1;
if k=1 then write('co') else write('khong');
readln
end.