var
xy:array [1..4,1..2] of integer;
kp:array [1..2,1..2] of real;
i:byte;
x,y:real;
g,f:text;
 Procedure CheckRule;
  Begin
   If (xy[1,1]=xy[2,1]) and (xy[3,1]<>xy[4,1]) then
    Begin
     kp[1,2]:=(xy[3,2]-xy[4,2])/(xy[3,1]-xy[4,1]);
     kp[2,2]:=xy[3,2]-kp[1,2]*xy[3,1];
     x:=xy[1,1];
     y:=kp[1,2]*x+kp[2,2];
    End
   else
    If (xy[3,1]=xy[4,1]) and (xy[1,1]<>xy[2,1]) then
     Begin
      kp[1,1]:=(xy[1,2]-xy[2,2])/(xy[1,1]-xy[2,1]);
      kp[2,1]:=xy[1,2]-kp[1,1]*xy[1,1];
      x:=xy[3,1];
      y:=kp[1,1]*x+kp[2,1];
     End
    else
     If (xy[1,1]<>xy[2,1]) and (xy[4,1]<>xy[4,2]) then
      Begin
       kp[1,1]:=(xy[1,2]-xy[2,2])/(xy[1,1]-xy[2,1]);
       kp[2,1]:=xy[1,2]-kp[1,1]*xy[1,1];
       kp[1,2]:=(xy[3,2]-xy[4,2])/(xy[3,1]-xy[4,1]);
       kp[2,2]:=xy[3,2]-kp[1,2]*xy[3,1];
       x:=(kp[2,2]-kp[2,1])/(kp[1,1]-kp[1,2]);
       y:=kp[1,1]*x+kp[2,1];
      End;
  End;
Begin
Assign(f,'input.txt');
Reset(f);
For i:=1 to 4 do
 ReadLn(f,xy[i,1],xy[i,2]);
Close(f);
CheckRule;
Assign(g,'output.txt');
ReWrite(g);
If (Abs((x-xy[1,1])/(xy[2,1]-xy[1,1]))<1) and (Abs((x-xy[3,1])/(xy[4,1]-xy[3,1]))<1) then WriteLn(g,'Intersect')
else WriteLn(g,'Do not intersect');
Close(g);
End.