This summer, ZXyang became so tired when doing the problems of Multi-University contests. So he decided to attend the Unified National Graduate Entrance Examination. This day, he sees a problem of series.
Let $S(x)$ be a function with $x$ as the independent variable. $S(x)$ can be represented by the formula as follow.
$$f(x)=\sum_{i=1}^n f_i(x)$$
$$S(x)=\sum_{j=1}^xf(j)$$
$f_i(x)$ is a function with $x$ as the independent variable. Furthermore. $f_i(x)$ belongs to the function set $F$.
$$
F=\left \{
C,
\frac{C}{x},
C\sin x,
C\cos x,
\frac{C}{\sin x},
\frac{C}{\cos x},
Cx,
C^x
\right \}
$$
$C$ is a constant integer ranging from $0$ to $10^9$.
ZXyang wonders if $S(x)$ is convergent. $S(x)$ is convergent if and only if $ \lim\limits_{x\to \infty}S(x)=c$, where $c$ is a constant.