#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <bits/stdc++.h>
#include <stack>
#include <map>
 
using namespace std;
 
#define For(i,j,n) for(int i=j;i<=n;i++)
#define mst(ss,b) memset(ss,b,sizeof(ss));
 
typedef  long long LL;
 
template<class T> void read(T&num) {
    char CH; bool F=false;
    for(CH=getchar();CH<‘0‘||CH>‘9‘;F= CH==‘-‘,CH=getchar());
    for(num=0;CH>=‘0‘&&CH<=‘9‘;num=num*10+CH-‘0‘,CH=getchar());
    F && (num=-num);
}
int stk[70], tp;
template<class T> inline void print(T p) {
    if(!p) { puts("0"); return; }
    while(p) stk[++ tp] = p%10, p/=10;
    while(tp) putchar(stk[tp--] + ‘0‘);
    putchar(‘\n‘);
}
 
const LL mod=1e9+7;
const double PI=acos(-1.0);
const int inf=1e9;
const int N=2e5+20;
const int maxn=1e4+220;
const double eps=1e-12;

int n,m,w[N],a[N],b[N],p[N];
int x,y;
vector<int>st[N],en[N];
int findset(int x)
{
    if(x==p[x])return x;
    return p[x]=findset(p[x]);
}
int same(int x,int y)
{
    int fx=findset(x),fy=findset(y);
    if(fx>fy)p[fy]=fx;
    else if(fx<fy)p[fx]=fy;
}
int main()
{
   while(scanf("%d%d",&n,&m)!=EOF)
   {
        For(i,1,n-1)read(w[i]);
        int high=max(n,m)+10;
        for(int i=0;i<=high;i++)
        {
            p[i]=i;
            st[i].clear();
            en[i].clear();
        }
        For(i,1,m)
        {
            read(a[i]);read(b[i]);
            if(a[i]>b[i])swap(a[i],b[i]);
            int r=a[i];
            while(1)
            {
                r=findset(r);
               if(r>=b[i])break;
               same(r,r+1);
               st[i].push_back(r);
            }
        }
        for(int i=0;i<=high;i++)p[i]=i;
        for(int i=m;i>0;i--)//找到第i天要关闭的线段
        {
            int r=a[i];
            while(1)
            {
                r=findset(r);
                if(r>=b[i])break;
                same(r,r+1);
                en[i].push_back(r);
            }
        }
        int ans=0;
        for(int i=1;i<=m;i++)
        {
            int len=st[i].size();
            for(int j=0;j<len;j++)//加上这一天要打开的线段
            {
                int x=st[i][j];
                ans+=w[x];
            }
            print(ans);
            len=en[i].size();
            for(int j=0;j<len;j++)//关闭这天需要关闭的线段;
            {
                int x=en[i][j];
                ans-=w[x];
            }
        }
   }
    return 0;
}