Cities and roads#992
In the Milky Way galaxy, on the planet Neptune, there are cities, some of which are connected by roads. Emperor Maximus of the Milky Way galaxy has decided to make an inventory of the roads on Neptune. However, as it turns out, he is not very good at math, so he asks you to count the number of roads.
The first line contains the number (0 \leq n \leq 100). Each of the next lines contains numbers, each either zero or one. If the position in the square matrix is one, then the -th and -th cities are connected by a road; if it is zero, they are not connected.
Print the number of roads on the planet Neptune.
Example 1