#include "bits/stdc++.h"

using namespace std;

using ll = long long;
using P = pair<ll, ll>;

struct Query
{
    using type = P;
    static type id() { return P(0, -1e15); }
    static type op(const type &l, const type &r) { return P(max(l.first + r.first, l.second + r.second), max(l.first + r.second, l.second + r.first)); }
};

template <typename M>
class SegmentTree
{
    using T = typename M::type;
    int n;
    std::vector<T> node;

  public:
    // v を基に初期化
    SegmentTree(const std::vector<T> &v)
    {
        // n は v.size() 以上の最小の2冪
        n = 1;
        while (n < int(v.size()))
            n *= 2;
        node.resize(2 * n - 1, M::id());

        // i の子 -> 2*i+1, 2*i+2 , 親 -> (i-1)/2
        for (int i = 0; i < int(v.size()); i++)
            node[i + n - 1] = v[i];
        for (int i = n - 2; i >= 0; i--)
            node[i] = M::op(node[2 * i + 1], node[2 * i + 2]);
    }
    // Monoid::id 初期化
    SegmentTree(int _n)
    {
        // n は v.size() 以上の最小の2冪
        n = 1;
        while (n < _n)
            n *= 2;
        node.resize(2 * n - 1, M::id());
    }
    // x 番目を val に更新
    void update(int x, T val)
    {
        x += n - 1;
        node[x] = val;
        while (x > 0)
        {
            x = (x - 1) / 2;
            node[x] = M::op(node[2 * x + 1], node[2 * x + 2]);
        }
    }
    // v[x] を M::op(v[x], val) に更新
    void add(int x, T val)
    {
        x += n - 1;
        node[x] = M::op(node[x], val);
        while (x > 0)
        {
            x = (x - 1) / 2;
            node[x] = M::op(node[2 * x + 1], node[2 * x + 2]);
        }
    }
    // [a, b) の op
    // k := 今居るノード
    T query(int a, int b, int k = 0, int l = 0, int r = -1)
    {
        if (r < 0)
            r = n;
        if (r <= a || b <= l)
            return M::id();
        if (a <= l && r <= b)
            return node[k];

        T vl = query(a, b, 2 * k + 1, l, (l + r) / 2);
        T vr = query(a, b, 2 * k + 2, (l + r) / 2, r);
        return M::op(vl, vr);
    }
};

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);

    int n, q;
    cin >> n >> q;
    vector<ll> a(2 * n), b(2 * n);
    vector<P> v;
    for (int i = 0; i < 2 * n; i++)
        cin >> a[i];
    for (int i = 0; i < 2 * n; i++)
    {
        cin >> b[i];
        v.emplace_back(P(a[i], b[i]));
    }
    SegmentTree<Query> st(v);
    while (q--)
    {
        ll p, x, y;
        cin >> p >> x >> y;
        p--;
        a[p] = x;
        b[p] = y;
        st.update(p, P(x, y));
        ll ret = a[0] + a[2 * n - 1] + st.query(1, 2 * n - 1).first;
        cout << ret << endl;
    }
}
