language: Pascal (gpc) (gpc 20070904)
date: 107 days 1 hour ago
link:
visibility: public 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22

var
 i, j, n, para, wag: integer;
 a: array[ 1..150 ] of integer;
begin
 readln( n );
 for i:= 1 to n do
  readln( a[ i ] );
 para:= 0;
 wag:= 0;
 
 for i:= 1 to n do
   for j:= 1 to n do
    if ( a[ i ] = a[ j ] ) and ( a[ i ] <> 0 ) and ( i<>j ) then
     begin
      a[ i ]:= 0;
      a[ j ]:= 0;
      para:= para + 1;
      break;
     end; 
  wag:= para div 4;
  writeln( wag )    
end.