/*
将原数组改写成差分数组，那么修改[l,r]区间的值就是对差分数组单点修改，求单点的值就是对差分数组求前缀和

差分：a是原数组，b是差分数组, a[0] == 0
b[1] = a[1] - a[0];  a[1] = b[1]
b[2] = a[2] - a[1];  a[2] = b[1] + b[2];
b[3] = a[3] - a[2];  a[3] = b[1] + b[2] + b[3];
.
.
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b[n] = a[n] - a[n-1] a[n] = b[1] + b[2] +...+ b[n]

对a[l ~ r]上加c, 即b[l] += c, b[r + 1] -= c;
例如：[1,3]
b[1] = a[1] + c;
b[2] = a[2] + c - (a[1] + c) = a[2] - a[1];
b[3] = a[3] + c - (a[2] + c) = a[3] - a[2];
b[4] = a[4] - (a[3] + c) = a[4] - a[3] - c;
b[5] = a[5] - a[4];


*/
#include <iostream>
#include <algorithm>
using namespace std;

typedef long long LL;
const int N = 100010;

int n, m;
int a[N], tr[N];

int lowbit(int x)
{
    return x & -x;
}
void add(int x, int c)
{
    for (int i = x; i <= n; i += lowbit(i)) tr[i] += c;
}

LL sum(int x)
{
    LL res = 0;
    for (int i = x; i; i -= lowbit(i)) res += tr[i];
    return res;
}

int main()
{
    scanf("%d%d",&n, &m);
    for (int i = 1; i <= n; i ++) scanf("%d",&a[i]);

    //将差分数组存入树状数组中
    for (int i = 1; i <= n; i ++) add(i, a[i] - a[i - 1]);

    while(m --)
    {
        char op[2];
        int l, r, d;
        scanf("%s%d",op,&l);
        if(op[0] == 'C')
        {
            scanf("%d%d", &r ,&d);
            add(l, d), add(r + 1, -d);
        }
        else
        {
            printf("%lld\n",sum(l));
        }
    }

    return 0;
}