Score : $100$ points
Snuke has a grid consisting of three squares numbered $1$, $2$ and $3$.
In each square, either
1 is written. The number written in Square $i$ is $s_i$.
Snuke will place a marble on each square that says
Find the number of squares on which Snuke will place a marble.
Input is given from Standard Input in the following format:
Print the answer.