n = int(input())
fac_2n = 1
fac_n = 1
for i in range(1,2*n+1):
    fac_2n = fac_2n*i


for i in range(1,n+1):
    fac_n = fac_n*i;

ans = int(fac_2n/(fac_n*fac_n*(n+1)))
print(ans)