import sys sys.setrecursionlimit(10**6) int1 = lambda x: int(x)-1 p2D = lambda x: print(*x, sep="\n") def II(): return int(sys.stdin.buffer.readline()) def LI(): return list(map(int, sys.stdin.buffer.readline().split())) def LI1(): return list(map(int1, sys.stdin.buffer.readline().split())) def LLI(rows_number): return [LI() for _ in range(rows_number)] def LLI1(rows_number): return [LI1() for _ in range(rows_number)] def BI(): return sys.stdin.buffer.readline().rstrip() def SI(): return sys.stdin.buffer.readline().rstrip().decode() # dij = [(0, 1), (-1, 0), (0, -1), (1, 0)] dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)] inf = 10**16 # md = 998244353 md = 10**9+7 n=II() dp=[[0]*(n+1) for _ in range(2*n+1)] dp[0][0]=1 for i in range(2*n): for j in range(n+1): if (i+j)&1:continue pre=dp[i][j] if pre==0:continue l=(i+j)//2 if l=0:dp[i+1][j-1]+=pre # p2D(dp) print(dp[-1][0])