# include <bits/stdc++.h>
# define ll long long
# define fi first
# define se second
# define pii pair<int, int>
using namespace std;

ll MOD;

ll fast(ll a, ll b) {
	if(b == 0) return 1ll % MOD;
	if(b == 1) return a % MOD;
	ll K = fast(a, b / 2ll);
	K *= K;
	K %= MOD;
	if(b&1) {
		K *= (a % MOD);
		K %= MOD;
	}
	return K;
}

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	
	int a, b, n;
	while(cin>>a>>b>>n>>MOD) {
		ll ans = 0ll;
		for(int i=n;i>=0;i-=2) {
			ans += (fast(a, i) * fast(b, (n - i) / 2))%MOD;
			ans %= MOD;
		}
		ans *= 2ll;
		ans %= MOD;
		cout<<ans<<"\n";
	}
}