program eulersum;
uses crt;
var n, x, i: integer;
S, f: real;
begin
clrscr;
write('Nhap n: ');
readln(n);
write('Nhap x: ');
readln(x);
S := x;
f := x;
for i := 1 to n-1 do
begin
f := f * (x/(i+1));
S := S + f;
end;
writeln('Tong S: ', S:5:2);
readln
end;