var n,i,q:integer;a1,a2,b1,b2,x,y,c,d:array[0..10] of real;l:real;

begin

readln(n);

for i:=1 to n do

readln(x[i],a1[i],b1[i],a2[i],b2[i]);

for i:=1 to n do

if (a1[i]5) then y[i]:=0

else if (a2[i]5) then y[i]:=0

else if (b2[i]5) then y[i]:=a1[i]

else if (b1[i]5) then

begin

if (5-b1[i])>(a2[i]-5) then y[i]:=a2[i]

else y[i]:=b1[i];

end;

i:=0;

q:=0;

repeat

q:=q+1;

i:=i+1;

if y[q]0 then begin c[i]:=y[q];d[i]:=x[q];end

else i:=i-1;

until q=n;

l:=0;

d[0]:=0;

c[0]:=5;

d:=10;

c:=5;

for q:=1 to i+1 do

l:=l+sqrt((d[q]-d[q-1])*(d[q]-d[q-1])+(c[q]-c[q-1])*(c[q]-c[q-1]));

writeln(l:0:2);

end.