#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
using ld=long double;
ll ILL=2167167167167167167;
const int INF=2100000000;
const int mod=998244353;
#define rep(i,a,b) for (ll i=a;i<b;i++)
#define all(p) p.begin(),p.end()
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";}
template<class T> void vec_out(vector<T> &p){for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}
template<class T> T min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;}
template<class T> T max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;}
template<class T> T sum(vector<T> &a){assert(!a.empty());T ans=a[0]-a[0];for(auto &x:a) ans+=x;return ans;}

ll jyo(ll x,ll y,ll z){
  ll H=y; //ここから
       ll a=1,b=(x%z+z)%z,c=1;
       while(H>0){
         a*=2;
         if(H%a!=0){
           H-=a/2;
           c*=b;
           c%=z;
         }
        b*=b;
         b%=z;
      } //ここまで
 return c;
}

//最大公約数
long long Gcd(long long a,long long b){
	if(b==0) return a;
	else return Gcd(b,a%b);
}

//最小公倍数
long long Lcm(long long a,long long b){
	return (a/Gcd(a,b))*b;
}
//カーマイケル数の出力
long long carmichael(long long a){
	long long ans=1,A=1;
	//2を素因数に持つときだけ場合わけ
	while(a%2==0) A*=2,a/=2;
	if(A==4) ans=2;
	else if(A>4) ans=A/4;
	A=a;
	for(long long k=3;k*k<=a;k++){
	//for(auto k:div){ //配列divをsqrt(a)以下の素数を全列挙するやつにする
		if(A%k==0){
			long long B=k-1;
			A/=k;
			while(A%k==0) A/=k,B*=k;
			ans=Lcm(ans,B);
		}
	}
	if(A!=1) ans=Lcm(ans,A-1);
	return ans;
}

namespace po167{
template<class T,T(*op)(T,T)>
struct Doubling_op
{
	int _n;
	long long Log;
	std::vector<std::vector<int>> index_data;
	std::vector<std::vector<T>> value_data;
	Doubling_op(int n,long long limit,std::vector<int> index,std::vector<T> value):_n(n){
		Log=2;
		while(limit){
			limit/=2;
			Log++;
		}
		index_data.resize(Log);
		value_data.resize(Log);
		index_data[0]=index;
		value_data[0]=value;
		for(int i=1;i<Log;i++){
			index_data[i].resize(_n);
			value_data[i].resize(_n);
			for(int j=0;j<_n;j++){
				int tmp=index_data[i-1][j];
				index_data[i][j]=index_data[i-1][tmp];
				value_data[i][j]=op(value_data[i-1][j],value_data[i-1][tmp]);
			}
		}
	}
	std::pair<int,T> query(long long times,int start_index,T start_value){
		for(int i=0;i<Log;i++){
			if(times&1){
				start_value=op(start_value,value_data[i][start_index]);
				start_index=index_data[i][start_index];
			}
			times>>=1;
		}
		return std::make_pair(start_index,start_value);
	}
};

struct Doubling
{
	int _n;
	long long Log;
	std::vector<std::vector<int>> index_data;
	Doubling(int n,long long limit,std::vector<int> index):_n(n){
		Log=2;
		while(limit){
			limit/=2;
			Log++;
		}
		index_data.resize(Log);
		index_data[0]=index;
		for(int i=1;i<Log;i++){
			index_data[i].resize(_n);
			for(int j=0;j<_n;j++){
				int tmp=index_data[i-1][j];
				index_data[i][j]=index_data[i-1][tmp];
			}
		}
	}
	int query(long long times,int start_index){
		for(int i=0;i<Log;i++){
			if(times&1){
				start_index=index_data[i][start_index];
			}
			times>>=1;
		}
		return start_index;
	}
};
}
using po167::Doubling_op;
using po167::Doubling;
using doubleing_F=long long;
doubleing_F d_op(doubleing_F l,doubleing_F r){
	return l+r;
}
 

void solve();
// oddloop
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int t=1;
	//cin>>t;
	rep(i,0,t) solve();
}

void solve(){
	ll M,D,N,B;
	cin>>M>>D>>N>>B;
	ll C=carmichael(B);
	ll X=8*11*7*9*5;
	auto f=[&](ll X)->void{
		X%=B;
		if(X==10) cout<<"A\n";
		else cout<<X%B<<"\n";
		exit(0);
	};
	if(N==0){
		f(M);
	}
	if(D==0){
		if(M==1||M==0){
			f(1);
		}
	}
	if(M==0){
		if(N==1){
			cout<<"1\n";
			return;
		}
		M=1,N--;
	}
	if(M==1){
		N--,M+=D;
	}
	if(M==2){
		if(N==0){
			f(2);
		}
		N--;
		M=jyo(M+D,2,X);
	}
	vector<int> to(X);
	rep(i,0,X) to[i]=jyo(i+D,X+i,X);
	Doubling p(X,N,to);
	ll ans=p.query(N,M%X)%B;
	if(ans==10) cout<<"A\n";
	else cout<<ans<<"\n";
}