#include<iostream>
#include<cstdio>
using namespace std;
long long n,a,k,p;
typedef long long ll;
ll ksm(ll a,ll b){
    ll res=1;
    while(b){
        if(b&1) res=res*a%p;
        a=a*a%p;
        b>>=1;
    }
    return res;
}
int main(){
    freopen("oeis.in","r",stdin);
    freopen("oeis.out","w",stdout);
    cin>>n>>a>>k>>p;
    ll ans=0;
    for(int i=1;i<=n;i++){
        ans=(ans+ksm(i,k)*ksm(a,i)%p)%p;
    }
    cout<<ans;
    return 0;
}