$20
There are N colors balls in a box. If you can get a pair of same color balls you win. find out how many balls you
need to take so that there is at least one matching pair.
Assume that there are indefinite number of balls available with given colors.
Example -
ifN = 5
It means there are indefinite number of 5 different color balls.
Input Format N = Number of colors Constraints
Output Format