from sys import stdin,stdout | |
def main(): | |
rt = [1] | |
for it in range(1,310): | |
rt.append(rt[it-1]*(it<<1)*((it<<1)-1)//(it+1)) | |
while True: | |
idx = int(stdin.readline()) | |
if idx==0: | |
break | |
stdout.write(str(rt[idx])+"\n") | |
if __name__ == "__main__": | |
main() | |