#include <bits/stdc++.h>
#define int long long
using namespace std;
const int MOD = 998244853;

signed main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int n, a, b, c;
    cin >> n >> a >> b >> c;
    int dp[n + 1];
    dp[0] = 1;
    for (int i = 1; i <= n; ++i) {
    	dp[i] = (dp[i - 1] * a) % MOD;
    	if (i > 1) dp[i] = (dp[i] + dp[i - 2] * b) % MOD;
    	if (i > 2) dp[i] = (dp[i] + dp[i - 3] * b) % MOD;
    }
    cout << dp[n];
    return 0;
}