program one;
var dx:integer;
s,x1,x2:real;
q:array[1..20] of real;
r:array[1..25] of real;
k:array[1..100] of real;
i:integer;x,qq,kk:integer;
function y(x:real):real;
begin
For i:=1 to 20 do begin
read(q[i]);
if ((q[i]>-1.2)and(q[i]<3.4)) then inc(qq);
end;
For i:=1 to 25 do begin
read(k[i]);
if ((q[i]>2.2) and (q[i]<5.34)) then inc(kk);
end;
if qq<kk then begin
qq:=qq+kk;
kk:=qq-kk;
qq:=qq-kk;
end;
y:=x/(sqrt(exp(x*ln(exp(1)))- exp((-x)*ln(exp(1)))));
End;
begin
assign(output,'output1.txt');
rewrite(output);
i:=kk;
while i<=qq do begin
x1:=y(q[i]+i*dx);
x2:=y(q[i]+i*dx+dx);
s:=s+(x1+x2)/2*dx;
i:=i+dx;
end;
writeln(s);
end.