var a: array[1..1000] of string;
var m,k,i,n:integer;
begin
m:=0;
read(n);
for i:= 1 to n do begin
read(a[i]);
end;
For i:=1 to n do begin
for k:=1 to n do begin
if i<>k then begin
if a[i]=a[k] then begin
a[i]:='0';
m:=m+1;
end;
end;
end;
end;
write(m);
end.

Edited by author 21.08.2010 05:02