#include<bits/stdc++.h>
#define int long long
using namespace std;
void ts(){cout<<"IAKIOI\n";}
inline int read(){
	int n=0,f=1,ch=getchar();
	while(ch<'0'||ch>'9'){
		if(ch=='-')f=-1;
		ch=getchar();
	}
	while(ch>='0'&&ch<='9'){
		n=n*10+ch-'0';
		ch=getchar();
	}
	return n*f;
}
const int mod=998244353;
struct mint{
    int x;mint(int o=0){x=o;}mint&operator+=(mint a){return(x+=a.x)%=mod,*this;}mint&operator-=(mint a){return(x+=mod-a.x)%=mod,*this;}
    mint&operator*=(mint a){return(x=1ll*x*a.x%mod),*this;}mint&operator^=( int b){mint a=*this;x=1;while(b)(b&1)&&(*this*=a,1),a*=a,b>>=1;return*this;}
    mint&operator/=(mint a){return*this*=(a^=mod-2);}friend mint operator+(mint a,mint b){return a+=b;}friend mint operator-(mint a,mint b){return a-=b;}
    friend mint operator*(mint a,mint b){return a*=b;}friend mint operator/(mint a,mint b){return a/=b;}friend mint operator^(mint a,int b){return a^=b;}
    mint operator-(){return 0-*this;}bool operator==(const mint b)const{return x==b.x;}
};
signed main(){
	int t=read();
	if(t<=3000){
		deque<int> q;
		while(t--){
			int ty=read();
			if(ty==1){int x=read();q.push_front(x);}
			if(ty==2){int x=read();q.push_back(x);}
			if(ty==3){q.pop_front();}
			if(ty==4){q.pop_back();}
			if(ty==5||ty==6){
				int k=read(),c=read();
				if(ty==5){
					int res=0;
					for(int i=0;i<c&&i*k<(int)q.size();i++)res+=q[i*k];
					printf("%lld\n",res);
				}
				else{
					int res=0;
					for(int i=0;i<c&&i*k<(int)q.size();i++){
						res+=q[(int)q.size()-1-i*k];
					}
					printf("%lld\n",res);
				}
			}
		}
		return 0;
	}
	return 0;
}