a)program oken;
uses crt;
var i,n,tong:integer;
begin
write('nhap so phan tu cua mang: '); readln(n);
tong:=1;
for i:=1 to (n+n+1)
if i mod 2=1 then tong:=tong+(1/i);
writeln('tong cua day so A: ',tong);
readln;
end.
b)
program oken;
uses crt;
var i,n,tong:integer;
begin
write('nhap so phan tu cua mang: '); readln(n);
tong:=1;
for i:=1 to (n+n)
if (i mod 2=0) and (n<>0) then tong:=tong+(1/i);
writeln('tong cua day so B: ',tong);
readln;
end.