import sys # sys.setrecursionlimit(200005) int1 = lambda x: int(x)-1 pDB = lambda *x: print(*x, end="\n", file=sys.stderr) p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr) def II(): return int(sys.stdin.readline()) def LI(): return list(map(int, sys.stdin.readline().split())) def LLI(rows_number): return [LI() for _ in range(rows_number)] def LI1(): return list(map(int1, sys.stdin.readline().split())) def LLI1(rows_number): return [LI1() for _ in range(rows_number)] def SI(): return sys.stdin.readline().rstrip() 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 = (1 << 63)-1 # inf = (1 << 31)-1 # md = 10**9+7 md = 998244353 n = II() m = n//3 dp = [[0]*3 for _ in range(m+1)] dp[0][0] = 1 for i in range(n): ndp = [[0]*3 for _ in range(m+1)] for j in range(i//3+1): for k in range(3): pre = dp[j][k] if pre==0:continue ndp[j][k] += pre*25%md ndp[j+(k == 2)][(k+1)%3] += pre ndp[j][k] %= md ndp[j+(k == 2)][(k+1)%3] %= md dp = ndp ans = 0 for j in range(m+1): ans += sum(dp[j])*j ans %= md print(ans)