#include <iostream>
#include <vector>
#include <algorithm>
 
using namespace std;
 
long long init(int start, int end, int node, vector<long long>& inputs, vector<long long>& segTree) {
    if(start==end) {
        return segTree[node]=inputs[start];
    }
 
    int mid=(start+end)/2;
    
    return segTree[node]=init(start, mid, node*2, inputs, segTree)+init(mid+1, end, node*2+1, inputs, segTree);
}
 
long long find(int start, int end, int node, int rangeLow, int rangeHigh, vector<long long>& segTree) {
    if(rangeHigh<start || rangeLow>end) return 0;
    if(start>=rangeLow && end<=rangeHigh) return segTree[node];
 
    int mid=(start+end)/2;
 
    return find(start, mid, node*2, rangeLow, rangeHigh, segTree)+find(mid+1, end, node*2+1, rangeLow, rangeHigh, segTree);
}
 
long long change(int start, int end, int node, int targetIndex, long long changeTo, vector<long long>& segTree) {
    if(start>targetIndex || end<targetIndex) return segTree[node];
    if(start==end) return segTree[node]=changeTo;
 
    int mid=(start+end)/2;
 
    return segTree[node]=change(start, mid, node*2, targetIndex, changeTo, segTree)+change(mid+1, end, node*2+1, targetIndex, changeTo, segTree);
}
 
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    
    int nodeNum, calNum;
    cin>>nodeNum>>calNum;
 
    vector<long long> inputs(nodeNum);
    for(int i=0; i<nodeNum; i++) {
        cin>>inputs[i];
    }
 
    vector<long long> segTree(400000, -1);
 
    init(0, nodeNum-1, 1, inputs, segTree);
 
    for(int i=0; i<calNum; i++) {
        int rangeLow, rangeHigh;
        cin>>rangeLow>>rangeHigh;
 
        if(rangeLow>rangeHigh) {
            swap(rangeLow, rangeHigh);
        }
 
        int targetIndex, changeTo;
        cin>>targetIndex>>changeTo;
 
        cout<<find(0, nodeNum-1, 1, rangeLow-1, rangeHigh-1, segTree)<<"\n";
        change(0, nodeNum-1, 1, targetIndex-1, changeTo, segTree);
    }
}