#define INF 0x3f3f3f3f 
using namespace std;
typedef long long LL;

namespace IO
{
    template<typename T>void write(T x)
    {
        if(x<0)
        {
            putchar('-');
            x=-x;
        }
        if(x>9) write(x/10);
        putchar(x%10+'0');
    }

    template<typename T> void read(T &x)
    {
        x = 0;char ch = getchar();int f = 1;
        while(!isdigit(ch)){if(ch == '-')f*=-1;ch=getchar();}
        while(isdigit(ch)){x = x*10+(ch-'0');ch=getchar();}x*=f;
    }
};
using namespace IO;

LL tree[500001];//树状数组 
LL A[500001];//原始区间序列 
//LL B[500001];//差分数组 
LL n,m;

inline LL lowbit(LL x){//本质是2^0,2^1...2^n 
	//一个非负整数n在二进制下的最低为1及其后面的0构成的数
	//(101100)2  -->  100;
	//(110010)2  -->  10;
    return x&(-x);
}

inline void update(LL x,LL value){//A[x]+value
	A[x]+=value;
	while (x<=n){
		tree[x]+=value;
		x+=lowbit(x);
	} 
}

inline LL getval(LL x){
	LL ans=0;
	while (x>0){
		ans+=tree[x];
		x-=lowbit(x);
	}
	return ans;
}
 
inline LL modify(LL left,LL right){//左右区间，查询left-right区间值的和 
	LL ans=0;
	ans+=getval(right)-getval(left-1);
	return ans;
}

signed main()
{
	memset(A,0,sizeof A);
	memset(tree,0,sizeof tree);
	LL val;LL op,x,y,k;LL save=0;
	cin>>n>>m;
	for (LL i=1;i<=n;i++){
		cin>>val; 
		update(i,val-save);
		save=val; 
	}
	for (LL i=1;i<=m;i++){
		cin>>op;
		if (op==1) {
			cin>>x>>y>>k;
			update(x,k);
			update(y+1,-k);
		}
		else{
			cin>>k;
			cout<<modify(1,k)<<endl;
		}
	}
	return 0;
}