F

#include <bits/stdc++.h>
using namespace std;

#define ll long long

int main()
{
    int t;
    cin>>t;

    while(t--)
    {
        ll n,q;
        cin>>n>>q;
        vector<ll> arr(n);
        for(int i=0;i<n;i++)
            cin>>arr[i];

        ll minn=arr[n-1];
        ll sum = accumulate(arr.begin(), arr.end(), 0ll);
        ll s = sum;
        for(int i=n-2;i>=0;i--)
        {
            if(arr[i]>=minn)
            {
                s-=minn;
                break;
            }
            else
            {
                s-=arr[i];
                minn=min(minn-arr[i],arr[i]);
            }
        }

        cout<<s<<"\n";

        while(q--)
        {
            ll x,y;
            cin>>x>>y;
            x--;
            sum += y - arr[x];
            arr[x]=y;
            ll minn=arr[n-1];
            ll s = sum;

            for(int i=n-2;i>=0;i--)
            {
                if(arr[i]>=minn)
                {
                    s-=minn;
                    break;
                }
                else
                {
                    s-=arr[i];
                    minn=min(minn-arr[i],arr[i]);
                }
            }

            cout<<s<<"\n";
        }
    }
}