Min → max, max → min

uses crt;
const n = 5;
var a,b:array[1..n] of real; i,k:integer; max, min:real;
begin
for i:=1 to n do begin
read(a[i]);
b[i]:=a[i];
end;
k:=0;
max:=a[1];
min:=a[1];
for i:=1 to n do begin
if (a[i] > max) then max:=a[i];
if (a[i] < min) then min:=a[i];
end;
for i:=1 to n do begin
if (a[i] = min) then begin inc(k); b[i]:=max; end;
if (a[i] = max) then  begin inc(k); b[i]:=min; end;
end;
if (k>2) then writeln('Максимальных и/или минимальных чисел несколько. Перестановка невозможна.')
else
for i:=1 to n do
write(b[i],' ');
writeln();
end.