1)var
a,b,h:real;
begin
readln(a);
readln(b);
readln(h);
while a begin
writeln(a,' ',2*cos(a)-1:8);
a+=h;
end
end.
2)var
eps,sum,current,n:real;
begin
readln(eps);
sum:=0;
n:=0;
repeat
current:=2*n-1/power(2,n);
n+=1;
sum+=current;
until current>eps;
writeln(sum);
end.