EXPLAIN THE OUTPUT

general
,
1

Please explain the output of the problem http://www.codechef.com/problems/DLCT06 . Number of ways 3 runs can be scored is 3, (1,1,1) , (1,2) and (2,1).

2

For the given problem set (1,2) and (2,1) is one and the same thing.

so for inputs

INPUT

2

3

4

OUTPUT

2

4

EXPLANATION

for N=3, two ways of getting a score of 3 are (1,2) and (1,1,1)

for N=4, four ways of getting a score of 4 are (1,1,1,1), (1,1,2), (2,2) and (4)