// clang-format off
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
template<class T> using V = vector<T>;
using VI = V<int>;
using VL = V<ll>;
using VS = V<string>;
template<class T> using PQ = priority_queue<T, V<T>, greater<T>>;
using G = V<VI>;
template<class T> using WG = V<V<pair<int, T>>>;
#define overload4(_1,_2,_3,_4,name,...) name
#define rep1(n) for(ll i=0;i<(n);++i)
#define rep2(i,n) for(ll i=0;i<(n);++i)
#define rep3(i,a,b) for(ll i=(a);i<(b);++i)
#define rep4(i,a,b,c) for(ll i=(a);i<(b);i+=(c))
#define rep(...) overload4(__VA_ARGS__,rep4,rep3,rep2,rep1)(__VA_ARGS__)
#define rrep1(n) for(ll i=n;i>0;--i)
#define rrep2(i,n) for(ll i=n;i>0;--i)
#define rrep3(i,a,b) for(ll i=b;i>a;--i)
#define rrep4(i,a,b,c) for(ll i=(a)+((b)-(a)-1)/(c)*(c);i>=(a);i-=c)
#define rrep(...) overload4(__VA_ARGS__,rrep4,rrep3,rrep2,rrep1)(__VA_ARGS__)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define inside(h,w,y,x) (unsigned(y)<h&&unsigned(x)<w)
#ifdef _DEBUG
#define line cout << "-----------------------------\n"
#define debug(...) print(__VA_ARGS__)
#else
#define line
#define debug
#endif
constexpr ll INF = 1000000000;
constexpr ll LLINF = 1LL << 61;
constexpr ll mod = 1000000007;
constexpr ll MOD = 998244353;
constexpr ld eps = 1e-10;
constexpr int dy[]{ -1,0,1,0 }, dx[]{ 0,1,0,-1 };
template<class T> inline bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; }return false; }
template<class T> inline bool chmin(T& a, const T& b) { if (a > b) { a = b; return true; }return false; }
inline void init() { cin.tie(nullptr); cout.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); }
template<class T> inline istream& operator>>(istream& is, V<T>& v) { for (auto& a : v)is >> a; return is; }
template<class T, class U> inline istream& operator>>(istream& is, pair<T, U>& p) { is >> p.first >> p.second; return is; }
template<class T> inline V<T> vec(size_t a) { return V<T>(a); }
template<class T> inline V<T> defvec(T def, size_t a) { return V<T>(a, def); }
template<class T, class... Ts> inline auto vec(size_t a, Ts... ts) { return V<decltype(vec<T>(ts...))>(a, vec<T>(ts...)); }
template<class T, class... Ts> inline auto defvec(T def, size_t a, Ts... ts) { return V<decltype(defvec<T>(def, ts...))>(a, defvec<T>(def, ts...)); }
template<class T> inline void print(const T& a) { cout << a << "\n"; }
template<class T, class... Ts> inline void print(const T& a, const Ts&... ts) { cout << a << " "; print(ts...); }
template<class T> inline void print(const V<T>& v) { for (int i = 0; i < v.size(); ++i)cout << v[i] << (i == v.size() - 1 ? "\n" : " "); }
template<class T> inline void print(const V<V<T>>& v) { for (auto& a : v)print(a); }
template<class T> inline constexpr const T cum(const V<T>& a, int l, int r) { return 0 <= l && l <= r && r < a.size() ? a[r] - (l == 0 ? 0 : a[l - 1]) : 0; }//[l,r]
template<class T> inline constexpr const auto min(const T& v) { return *min_element(all(v)); }
template<class T> inline constexpr const auto max(const T& v) { return *max_element(all(v)); }
template<class T> inline V<T>& operator++(V<T>& v) { for (T& a : v)++a; return v; }
template<class T> inline V<T>& operator--(V<T>& v) { for (T& a : v)--a; return v; }
// clang-format on

class combination {
    int n;
    ll c_mod;
    VL fac, finv, inv;

public:
    combination(int n, ll c_mod) : n(n), c_mod(c_mod), fac(n), finv(n), inv(n) {
        fac[0] = fac[1] = 1;
        finv[0] = finv[1] = 1;
        inv[1] = 1;
        for (int i = 2; i < n; ++i) {
            fac[i] = fac[i - 1] * i % c_mod;
            inv[i] = c_mod - inv[c_mod % i] * (c_mod / i) % c_mod;
            finv[i] = finv[i - 1] * inv[i] % c_mod;
        }
    }
    ll operator()(int n, int k) {
        if (n < k) return 0;
        if (n < 0 || k < 0) return 0;
        return fac[n] * (finv[k] * finv[n - k] % c_mod) % c_mod;
    }
};

#include <atcoder/modint>
using mint = atcoder::modint998244353;

int main() {
    init();

    int n;
    cin >> n;

    auto dp = vec<mint>(3, n);
    dp[0][0] = 1;
    rep(_, n) {
        auto nxt = vec<mint>(3, n);
        rep(k, n) {
            nxt[0][k] += dp[0][k] * 25;
            nxt[1][k] += dp[0][k];
            nxt[1][k] += dp[1][k] * 25;
            nxt[2][k] += dp[1][k];
            nxt[2][k] += dp[2][k] * 25;
            if (k + 1 < n) {
                nxt[0][k + 1] += dp[2][k];
            }
        }
        dp.swap(nxt);
    }
    mint ans = 0;
    rep(j, 3) rep(k, n) ans += dp[j][k] * k;
    print(ans.val());

    return 0;
}