# 线性DP
mod = 998244353
n = eval(input())
f = [0]*(n+1)

jiecheng = [1]*(n+1)
for i in range(2,n+1):
    jiecheng[i] = jiecheng[i-1]*i % mod

for i in range(2,n+1):
    f[i] = i*f[i-1] + (i-1)*i//2* jiecheng[i-1]
    f[i] %= mod
print(f[n])