#include <stdio.h>
#include <stdlib.h>

#define MOD 998244353

int bp(int a, int b) {
	if (! b) return 1;
	int r = bp(a, b >> 1);
	if ((b & 1)) return (long long)r * r % MOD * a % MOD;
	return (long long)r * r % MOD;
}

#define A 45
#define N 250005

int inv[A], p[N], ip[N], a[N], n
	, dp[N], mm[A], cc[A]
	, cnt[N], cntby[A]
	;

int main() {
	scanf("%d", &n);
	for (int i = 0; i < A; ++i)
		inv[i] = bp(i, MOD - 2);
	p[0] = ip[0] = 1;
	for (int i = 1; i <= n; ++i) {
		scanf("%d", a + i);
		p[i] = (long long)p[i - 1] * a[i] % MOD;
		ip[i] = (long long)ip[i - 1] * inv[a[i]] % MOD;
	}

	cnt[0] = 1;
	for (int i = 1; i <= n; ++i) {
		cntby[a[i]] = (cntby[a[i]] + cnt[i - 1]) % MOD;
		mm[a[i]] = (mm[a[i]] + (long long)ip[i - 1] * cnt[i - 1] % MOD) % MOD;
		cc[a[i]] = (cc[a[i]] + dp[i - 1]) % MOD;
		dp[i] = ((long long)mm[a[i]] * p[i] % MOD + cc[a[i]]) % MOD;
		cnt[i] = cntby[a[i]];
	}
	printf("%d\n", dp[n]);

	return 0;
}