EDITOR

#define task "EDITOR"
#include <iostream>
#include <cstdio>

using namespace std;

using ll = long long;
using ld = long double;
constexpr int N = 2e5 + 5;
constexpr ll Inf = 1e17;
int n, q;
ll a[N], pref[N], suf[N], b[N];

void Read()
{
    cin >> n >> q;

    for (int i = 1; i <= n; ++i)
        cin >> a[i];
}

void Solve()
{
    pref[0] = suf[0] = -Inf;

    for (int i = 1; i <= n; ++i)
    {
        a[i] += a[i - 1];
        pref[i] = max(pref[i - 1], a[i]);
    }

    int m1 = n, m2 = 0;
    ll up(0);

    while (q--)
    {
        char t;
        int x;
        cin >> t;

        if (t == 'A')
        {
            cin >> x;

            ++m1;
            a[m1] = a[m1 - 1] + x;
            pref[m1] = max(pref[m1 - 1], a[m1]);
        }
        else if (t == 'D')
        {
            --m1;
        }
        else if (t == 'L')
        {
            x = a[m1] - a[m1 - 1];
            --m1;

            up += x;
            ++m2;
            b[m2] = x - up;
            suf[m2] = max(suf[m2 - 1], b[m2]);
        }
        else if (t == 'R')
        {
            x = b[m2] + up;
            up -= x;
            --m2;

            ++m1;
            a[m1] = a[m1 - 1] + x;
            pref[m1] = max(pref[m1 - 1], a[m1]);
        }
        else
        {
            cout << max(pref[m1], suf[m2] + up + a[m1]) << "\n";
        }
    }
}

int32_t main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    if (fopen(task ".INP", "r"))
    {
        freopen(task ".INP", "r", stdin);
        freopen(task ".OUT", "w", stdout);
    }
    Read();
    Solve();
}