#include <cstdio>

 #include <cstring>

 #include <algorithm>

 #include <queue>

 #define inc(i,j,k) for(int i=j;i<=k;i++)

 #define maxn 60010

 #define INF 0x3fffffff

 using namespace std;

 inline int read(){

     char ch=getchar(); int f=,x=;

     while(ch<''||ch>''){if(ch=='-')f=-; ch=getchar();}

     while(ch>=''&&ch<='')x=x*+ch-'',ch=getchar();

     return f*x;

 }

 struct e{int t,c,n;}es[maxn*]; int g[maxn],ess;

 void pe(int f,int t,int c){

     es[++ess]=(e){t,c,g[f]}; g[f]=ess; es[++ess]=(e){f,,g[t]}; g[t]=ess;

 }

 int h[maxn]; queue<int>q;

 bool bfs(int s,int t){

     memset(h,-,sizeof(h)); while(!q.empty())q.pop(); h[s]=; q.push(s);

     while(!q.empty()){

         int x=q.front(); q.pop();

         for(int i=g[x];i;i=es[i].n)if(es[i].c&&h[es[i].t]==-)h[es[i].t]=h[x]+,q.push(es[i].t);

     }

     return h[t]!=-;

 }

 int dfs(int x,int t,int f){

     if(x==t)return f; int u=,w;

     for(int i=g[x];i;i=es[i].n)if(es[i].c&&h[es[i].t]==h[x]+){

         w=dfs(es[i].t,t,min(f,es[i].c)); f-=w; u+=w; es[i].c-=w; es[i^].c+=w; if(!f)return u;

     }

     if(!u)h[x]=-; return u;

 }

 int dinic(int s,int t){int f=; while(bfs(s,t))f+=dfs(s,t,INF); return f;}

 int n,m,s,t;

 int main(){

     n=read(); m=read(); s=read(); t=n+read(); ess=; inc(i,,n){int x=read(); pe(i,n+i,x);}

     inc(i,,m){int x=read(),y=read(); pe(n+x,y,INF); pe(n+y,x,INF);} printf("%d",dinic(s,t)); return ;

 }