\begin{array}{lll}
f(\varepsilon)&=&12+22\varepsilon^2+32\varepsilon^4+\cdots+9952\varepsilon^{1988}+\\
&&+9962\varepsilon^{995}+9972\varepsilon^{997}+\cdots+19902\varepsilon^{2983}=\\
&=&(12+22\varepsilon^2+32\varepsilon^4+\cdots+9952\varepsilon^{1988})+\Big((12+22\varepsilon^2+32\varepsilon^4+\cdots+9952\varepsilon^{1988})\varepsilon^{995}+9950\varepsilon^{995}(1+\varepsilon^2+\varepsilon^4+\cdots+\varepsilon^{1988})\Big)=\\
&=&(12+22\varepsilon^2+32\varepsilon^4+\cdots+9952\varepsilon^{1988})(1+\varepsilon^{995})+9950\varepsilon^{995}\frac{\varepsilon^{1990}-1}{\varepsilon^2-1}=\\
&=&(12+22\varepsilon^2+32\varepsilon^4+\cdots+9952\varepsilon^{1988})(1-1)+9950\varepsilon^{995}\frac{1-1}{\varepsilon^2-1}=\\
&=&0\end{array}