A new virus called a worm spreads through a network. When a computer becomes infected with the worm, all computers connected to it through the network become infected as well.

For example, suppose seven computers are connected as in Figure 1. If computer 1 is infected, the worm spreads through computers 2 and 5 to computers 3 and 6, infecting the four computers 2, 3, 5, and 6. However, computers 4 and 7 are unaffected because they are not connected to computer 1 through the network.

One day, computer 1 became infected with the worm. Given the number of computers and information about their network connections, write a program that prints the number of computers that become infected through computer 1.

Input

The first line contains the number of computers. There are at most 100 computers, numbered consecutively starting from 1.

The second line contains the number of pairs of computers directly connected through the network.

That many lines follow, each containing the numbers of one pair of directly connected computers.

Output

Print on the first line the number of computers that become infected through computer 1 when computer 1 is infected with the worm.

Examples

Input 1

7
6
1 2
2 3
1 5
5 2
5 6
4 7

Output 1

4