#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#define rc(x) return cout<<x<<endl,0
#define pb push_back
#define mkp make_pair
#define in insert
#define er erase
#define fd find
#define fr first
#define sc second
typedef long long ll;
typedef long double ld;
const ll INF=0x3f3f3f3f3f3f3f3f;
const ll llinf=(1LL<<62);
const int inf=(1<<30);
const int nmax=5e5+50;
const int mod=1e9+7;
using namespace std;
int n,m,i,ex[nmax],ey[nmax],deg[nmax],vl[nmax],vl1[nmax],rs[nmax],viz[nmax],g[nmax],cur,x,y,st;
vector<int>vc,a[nmax];
queue<int>q;
int main()
{
//freopen("sol.in","r",stdin);
//freopen("sol.out","w",stdout);
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
ios_base::sync_with_stdio(false);cin.tie(0);cerr.tie(0);cout.tie(0);
cin>>n>>m;
if(m>n)rc(0);
for(i=1;i<=n;i++)cin>>g[i];
for(i=1;i<=m;i++)
{
cin>>ex[i]>>ey[i];
a[ex[i]].pb(i);
a[ey[i]].pb(i);
}
for(i=1;i<=n;i++)
{
deg[i]=(int)a[i].size();
if(deg[i]==1)q.push(i),viz[i]=1;
}
while(!q.empty())
{
x=q.front();
q.pop();
for(i=0;i<(int)a[x].size();i++)
{
y=ex[a[x][i]]^ey[a[x][i]]^x;
if(!deg[y])continue;
rs[a[x][i]]=2*(g[x]-vl[x]);
vl[y]+=g[x]-vl[x];
vl[x]=g[x];
deg[y]--;
deg[x]--;
if(deg[y]==1)
{
viz[y]=1;
q.push(y);
}
}
}
for(i=1;i<=n;i++)if(deg[i])x=i;
st=x;
if(st)
{
while(1)
{
for(i=0;i<(int)a[x].size();i++)
{
y=ex[a[x][i]]^ey[a[x][i]]^x;
if(!deg[y])continue;
vc.pb(a[x][i]);
x=y;
break;
}
if(st==x)break;
}
if((int)vc.size()&1)rc(0);
for(i=1;i<=n;i++)vl1[i]=vl[i];
x=st;
for(i=0;i<(int)vc.size();i++)
{
y=ex[vc[i]]^ey[vc[i]]^x;
vl1[y]+=g[x]-vl1[x];
vl1[x]=g[x];
x=y;
}
cur=(g[x]-vl1[x])/2;
x=st;
for(i=0;i<(int)vc.size();i++)
{
y=ex[vc[i]]^ey[vc[i]]^x;
cur+=g[x]-vl[x];
vl[y]+=cur;
vl[x]+=cur;
rs[vc[i]]=2*cur;
cur=0;
x=y;
}
}
for(i=1;i<=m;i++)cout<<rs[i]<<'\n';
return 0;
}
