Uses Crt;
Var x1,x2,x3,y1,y2,y3,a,b,c : real;
Begin
 ClrScr;
 write('x1=');
 Readln(x1);
 write('y1=');
 Readln(y1);
 write('x2=');
 Readln(x2);
 write('y2=');
 Readln(y2);
 Write('x3=');
 Readln(x3);
 write('y3=');
 Readln(y3);
 a:=sqrt(sqr(x1-x2)+sqr(y1-y2));
 b:=sqrt(sqr(x2-x3)+sqr(y2-y3));
 c:=sqrt(sqr(x1-x3)+sqr(y1-y3));
 If (a=b)or(a=c)or(b=c) Then Write('равнобедренный')
 Else Write('не равнобедренный');
 ReadLn;
End.