uses crt;
var a,b,e,h,s,x,y: real;
i,n: integer;
function f(x: real): real;
begin
f:=ln(x*x+1)/(ln(10)*x);
end;
begin
clrscr;
a:=0.8;
b:=1.6;
e:=0.005;
n:=round((b-a)/e);
for i:=1 to n-1 do
begin
x:=a+i*e;
s:=s+f(x);
end;
y:=e*((f(a)+f(b))/2+s);
writeln('S=',y:0:3);
readln
end.