#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

int main() {

    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    //freopen("input.txt", "r", stdin);

    ll n;
    cin >> n;
    vector<ll> a(n);
    for (int i = 0; i < n; i++) cin >> a[i];

    vector<vector<ll> > dp(n, vector<ll>(4));
    dp[0][0] = 0;
    dp[0][1] = 0;
    dp[0][2] = 0;
    dp[0][3] = 0;

    for (int i = 1; i < n; i++) {

        for (int j = 0; j < 4; j++) {
                dp[i][0] = max(dp[i][0], dp[i - 1][j]);
        }

        dp[i][1] = dp[i - 1][0] + a[i];
        dp[i][2] = dp[i - 1][1] + a[i];
        dp[i][3] = dp[i - 1][2] + a[i];

    }

    ll ans = dp[n - 1][0];
    for (int j = 1; j <= 3; j++) {
        ans = max(ans, dp[n - 1][j]);
    }


    dp.assign(n, vector<ll>(4));
    dp[0][0] = 0;
    dp[0][1] = a[0];
    dp[0][2] = 0;
    dp[0][3] = 0;

    for (int i = 1; i < n; i++) {

        for (int j = 0; j < 4; j++) {
                dp[i][0] = max(dp[i][0], dp[i - 1][j]);
        }

        dp[i][1] = dp[i - 1][0] + a[i];
        dp[i][2] = dp[i - 1][1] + a[i];
        dp[i][3] = dp[i - 1][2] + a[i];

    }

    ans = max(ans, dp[n - 1][0]);



    dp.assign(n, vector<ll>(4));
    dp[0][0] = 0;
    dp[0][1] = 0;
    dp[0][2] = a[0];
    dp[0][3] = 0;

    for (int i = 1; i < n; i++) {

        for (int j = 0; j < 4; j++) {
                dp[i][0] = max(dp[i][0], dp[i - 1][j]);
        }

        dp[i][1] = dp[i - 1][0] + a[i];
        dp[i][2] = dp[i - 1][1] + a[i];
        dp[i][3] = dp[i - 1][2] + a[i];

    }

    ans = max(ans, dp[n - 1][0]);
    for (int j = 1; j <= 1; j++) {
        ans = max(ans, dp[n - 1][j]);
    }


    dp.assign(n, vector<ll>(4));
    dp[0][0] = 0;
    dp[0][1] = 0;
    dp[0][2] = 0;
    dp[0][3] = a[0];

    for (int i = 1; i < n; i++) {

        for (int j = 0; j < 4; j++) {
                dp[i][0] = max(dp[i][0], dp[i - 1][j]);
        }

        dp[i][1] = dp[i - 1][0] + a[i];
        dp[i][2] = dp[i - 1][1] + a[i];
        dp[i][3] = dp[i - 1][2] + a[i];

    }

    ans = max(ans, dp[n - 1][0]);
    for (int j = 1; j <= 2; j++) {
        ans = max(ans, dp[n - 1][j]);
    }


    cout << ans << "\n";
    ll q;
    cin >> q;

    while (q--) {

    ll b, c;
    cin >> b >> c;
    a[b - 1] = c;
    dp.assign(n, vector<ll>(4));
    dp[0][0] = 0;
    dp[0][1] = 0;
    dp[0][2] = 0;
    dp[0][3] = 0;

    for (int i = 1; i < n; i++) {

        for (int j = 0; j < 4; j++) {
                dp[i][0] = max(dp[i][0], dp[i - 1][j]);
        }

        dp[i][1] = dp[i - 1][0] + a[i];
        dp[i][2] = dp[i - 1][1] + a[i];
        dp[i][3] = dp[i - 1][2] + a[i];

    }

    ll ans = dp[n - 1][0];
    for (int j = 1; j <= 3; j++) {
        ans = max(ans, dp[n - 1][j]);
    }


    dp.assign(n, vector<ll>(4));
    dp[0][0] = 0;
    dp[0][1] = a[0];
    dp[0][2] = 0;
    dp[0][3] = 0;

    for (int i = 1; i < n; i++) {

        for (int j = 0; j < 4; j++) {
                dp[i][0] = max(dp[i][0], dp[i - 1][j]);
        }

        dp[i][1] = dp[i - 1][0] + a[i];
        dp[i][2] = dp[i - 1][1] + a[i];
        dp[i][3] = dp[i - 1][2] + a[i];

    }

    ans = max(ans, dp[n - 1][0]);



    dp.assign(n, vector<ll>(4));
    dp[0][0] = 0;
    dp[0][1] = 0;
    dp[0][2] = a[0];
    dp[0][3] = 0;

    for (int i = 1; i < n; i++) {

        for (int j = 0; j < 4; j++) {
                dp[i][0] = max(dp[i][0], dp[i - 1][j]);
        }

        dp[i][1] = dp[i - 1][0] + a[i];
        dp[i][2] = dp[i - 1][1] + a[i];
        dp[i][3] = dp[i - 1][2] + a[i];

    }

    ans = max(ans, dp[n - 1][0]);
    for (int j = 1; j <= 1; j++) {
        ans = max(ans, dp[n - 1][j]);
    }


    dp.assign(n, vector<ll>(4));
    dp[0][0] = 0;
    dp[0][1] = 0;
    dp[0][2] = 0;
    dp[0][3] = a[0];

    for (int i = 1; i < n; i++) {

        for (int j = 0; j < 4; j++) {
                dp[i][0] = max(dp[i][0], dp[i - 1][j]);
        }

        dp[i][1] = dp[i - 1][0] + a[i];
        dp[i][2] = dp[i - 1][1] + a[i];
        dp[i][3] = dp[i - 1][2] + a[i];

    }

    ans = max(ans, dp[n - 1][0]);
    for (int j = 1; j <= 2; j++) {
        ans = max(ans, dp[n - 1][j]);
    }


    cout << ans << "\n";

    }

}