What's wrong here? All the formulas are abviously correct,
but wwhy do I get WA?
By the way, in some discussions on this problem the author
(s) Li,Yi had the same problem, and somebody said "try :'if
way < 99.95 then ...", but this doesn't work with my
program as well.

Program Titanic;
 Const di=6875; r=di/2;
 Var u1,u2,u3,v1,v2,v3:Longint;
     a,b:Extended;
     x1,y1,z1,x2,y2,z2:Extended;
     c:Char;
     s:String;
     d1,d2,d3:Extended;
     cs,sn,al:Extended;
 Function StrToInt(s:String):Longint;
  Var Cod:Integer;
      v:Longint;
 Begin
  Val(s,v,Cod);
  StrToInt:=v;
 End;
 Function RR(st:Char):String;
  Var s:String;
      c:Char;
 Begin
  s:='';
  Repeat
   Read(c);
   If c In ['0'..'9'] Then
    s:=s+c;
  Until c=st;
  RR:=s;
 End;
 Function D(x1,y1,z1,x2,y2,z2:Extended):Extended;
 Begin
  D:=Sqrt(Sqr(x1-x2)+Sqr(y1-y2)+Sqr(z1-z2));
 End;
 Function SSin(a:Extended):Extended;
 Begin
  SSin:=sin(a/180*Pi);
 End;
 Function CCos(a:Extended):Extended;
 Begin
  CCos:=cos(a/180*Pi);
 End;
Begin
 While Not Eof Do Begin
  Readln;
  Readln;
  Readln;
  u1:=StrToInt(RR('^'));
  u2:=StrToInt(RR(''''));
  u3:=StrToInt(RR('"'));
  Readln(s);
  If Pos('N',s)>0 Then Begin
   u1:=-u1;
   u2:=-u2;
   u3:=-u3;
  End;
  v1:=StrToInt(RR('^'));
  v2:=StrToInt(RR(''''));
  v3:=StrToInt(RR('"'));
  Readln(s);
  If Pos('W',s)>0 Then Begin
   v1:=-v1;
   v2:=-v2;
   v3:=-v3;
  End;
  a:=u1+u2/60+u3/60/60;
{  a:=90-Abs(a);}
  b:=v1+v2/60+v3/60/60;
  x1:=ccos(a)*ccos(b);
  y1:=ccos(a)*ssin(b);
  z1:=ssin(a);
  Readln;
  u1:=StrToInt(RR('^'));
  u2:=StrToInt(RR(''''));
  u3:=StrToInt(RR('"'));
  Readln(s);
  If Pos('N',s)>0 Then Begin
   u1:=-u1;
   u2:=-u2;
   u3:=-u3;
  End;
  v1:=StrToInt(RR('^'));
  v2:=StrToInt(RR(''''));
  v3:=StrToInt(RR('"'));
  Readln(s);
  If Pos('W',s)>0 Then Begin
   v1:=-v1;
   v2:=-v2;
   v3:=-v3;
  End;
  a:=u1+u2/60+u3/60/60;
{  a:=90-Abs(a);}
  b:=v1+v2/60+v3/60/60;
  x2:=ccos(a)*ccos(b);
  y2:=ccos(a)*ssin(b);
  z2:=ssin(a);
  d1:=D(0,0,0,x1,y1,z1);
  d2:=D(0,0,0,x2,y2,z2);
  d3:=D(x2,y2,z2,x1,y1,z1);
  cs:=(d1*d1+d2*d2-d3*d3)/(2*d1*d2);
  sn:=Sqrt(Abs(1-cs*cs));
  If cs=0 Then
   al:=Pi/2
  Else
   al:=Arctan(sn/cs);
  If cs<0 Then
   al:=al+Pi;
  Writeln('The distance to the iceberg: ',al*r:0:2,'
miles.');
  If al*r<100 Then
   Writeln('DANGER!');
  Readln;
 End;
End.