#include<bits/stdc++.h>
#define L(i, j, k) for(int i = (j); i <= (k); ++i)
#define R(i, j, k) for(int i = (j); i >= (k); --i)
#define vi vector < int >
#define ll long long 
#define ull unsigned long long 
#define sz(a) ((int) (a).size())
#define me(a, x) memset(a, x, sizeof(a))
using namespace std;
const int N = 1e5 + 7, M = 1e4 + 7, mod = 998244353;

int n, m, c[N];
ll G[N];
vi e[N];

int main() {
	ios :: sync_with_stdio(false);
	cin.tie(0); cout.tie(0);
	cin >> n >> m;
	L(i, 1, n) {
		cin >> c[i];
	}
	L(i, 1, m) {
		int u, v;
		cin >> u >> v;
		e[u].emplace_back(v);
	}
	
	for(auto &v : e[1]) 
		G[v] += 1;
	
	int p = 1, ns = c[1];
	while(p <= n) {
		int pos = p + 1;
		while(pos <= n && !G[pos]) ++pos;
		if(pos > n) break;
		p = pos;
		int g = __gcd(G[pos], (ll) c[pos]);
		int cnt = c[pos] / g;
		int s = G[pos] / g;
		L(j, pos + 1, n) G[j] *= cnt;
		for(auto &v : e[pos]) G[v] += s;
		L(i, pos + 1, n) {
			ll dv = G[i] / c[i];
			G[i] %= c[i];
			for(auto &v : e[i]) G[v] += dv;
		}
		ns = (ll) ns * cnt % mod;
		if(pos > n) break;
	}
	cout << ns << '\n';
	return 0;
}