5. Calculate the sum of the expressions $S_{2015}$ and $S_{2016}$ if $S_{2015}=1-2+3-4+5-\ldots-2014+2015$, and $S_{2016}=1-2+3-4+5-\ldots-2014+2015-2016$.

Problems worth 10 points:
First method:
```
\(S_{2015}=(1-2)+(3-4)+\ldots+(2013-2014)+2015=(2014: 2) \cdot(-1)+2015=-1007+2015=\)
    \(=1008 \quad 3\) POINTS
\(S_{2016}=(1-2)+(3-4)+\ldots+(2015-2016)=(2016: 2) \cdot(-1)=-1008 \quad 2\) POINTS
\(S_{2015}+S_{2016}=1008+(-1008)=0\)
1 POINT
```

TOTAL 6 POINTS