program bac2010;
uses wincrt;
type
tab=array[1..10,'A'..'J'] of integer;
mat=array['A'..'J','A'..'J'] of real;
var
n:integer;
t:tab;
i:char;
M:mat;

procedure remplir(var T:tab;n:integer);
var
c:char;

begin
 for c:='A' to chr(n+64) do
  begin
   writeln('donner X',c);
   readln(T[1,c]);
   write('donner Y',c);
   read(T[2,c]);

end;
end;
function distance(T:tab;i,j:char):real;
var
d:real;
begin
d:=sqrt(sqr(T[1,i]-T[1,j])+sqr(T[2,i]-T[2,j]));
distance:=d;
end;

function proche(M:mat;i:char;n:integer):char;
var
j:char;
p:real;
begin
p:=M[i,'A'];
for j:='A' to chr(n+65) do
 if (j<>i) then
   if M[i,j]<p then
    begin
     p:=M[i,j];
     proche:=j;
    end;
end;
procedure remplir_M(var M:mat; t:tab; n:integer);

var i,j:char;

begin
for i:='A' to chr(n+64) do
 for j:='A' to chr(n+65) do
   if i=j then M[i,j]:=0
   else
   M[i,j]:=distance(T,i,j);
end;





begin
repeat read(n) until n in [3..10] ;
remplir(T,n);
remplir_M(M,T,n);
write('Donner un point du tableau');
read(i);
writeln('Le point le plus proche de ',i,' est ', proche(M,i,n));
end.