program bai1;
var a:array[1..100] of longint;
s:real,i,n:longint;
begin
repeat
write('N= ');
readln(n);
until n>0;
for i:=1to n do
begin
write('a[',i,']= ');
readln(a[i]);
end;
s:=0;
for i:=1o n do
s:=s+1/i;
write('S= ',s);
readln
end.