uses crt;
var xa,ya,xb,yb:integer;
kc:real;
{------------------------chuong-trinh-con-nhap----------------------------}
procedure nhap(var xc,yc,xd,yd:integer);
begin
write('Nhap toa do cua diem thu nhat:'); readln(xc,yc);
write('Nhap toa do cua diem thu hai:'); readln(xd,yd);
end;
{------------------------chuong-trinh-chinh------------------------------}
begin
clrscr;
nhap(xa,ya,xb,yb);
kc:=sqrt(sqr(xa-xb)+sqr(ya-yb));
writeln('Khoang cach giua hai diem la: ',kc:4:2);
readln;
end.