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)