网络流（小常数）

#include<bits/stdc++.h>
using namespace std;
const int inf=1000000007;
struct edg{int y,nxt,v;}e[41000];  
int lk[210],ltp=1;
int n,m,o,a[210];  
int s,t;
int lvl[210];
int q[210],hd=0;
int crt[210];
void addE(int x,int y,int v){
    e[++ltp]=(edg){y,lk[x],v};  lk[x]=ltp;
    e[++ltp]=(edg){x,lk[y],0};  lk[y]=ltp;
}
int rd(){int z=0,mk=1;  char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')mk=-1;  ch=getchar();}
    while(ch>='0'&&ch<='9'){z=(z<<3)+(z<<1)+ch-'0';  ch=getchar();}
    return z*mk;
}
bool bfs(){
    for(int i=s;i<=t;++i)  lvl[i]=0;
    lvl[(q[(hd=1)]=s)]=1;
    for(int k=1;k<=hd;++k){
        crt[q[k]]=lk[q[k]];
        for(int i=lk[q[k]];i;i=e[i].nxt)if(e[i].v && !lvl[e[i].y]){
            lvl[e[i].y]=lvl[q[k]]+1;
            q[++hd]=e[i].y;
        }
    }
    return lvl[t];
}
int dfs(int x,int y){
    if(x==t)  return y;
    int bwl=0,flw=0;
    for(int i=crt[x];i && bwl<y;i=e[i].nxt)if(lvl[e[i].y]==lvl[x]+1 && e[i].v)
        if((flw=dfs(e[i].y,min(e[i].v,y-bwl)))){
            e[i].v-=flw,e[i^1].v+=flw;
            bwl+=flw;
            if(!e[i].v)  crt[x]=e[i].nxt;
        }
    if(!bwl)  lvl[x]=0;
    return bwl;
}
int dinic(){
    int bwl=0,flw=0;
    while(bfs())while((flw=dfs(s,inf))){
        bwl+=flw;
    }
    return bwl;
}
void solve(){
    int ans=0;
    s=0;
    t=n+m+1;
    for(int i=s;i<=t;i++){
        lk[i]=0;
    }
    ltp=1;
    for(int i=1;i<=n;i++){
        a[i]=rd();
        addE(s,i,a[i]);
        ans+=a[i];
    }
    for(int i=1;i<=m;i++){
        a[i+n]=rd();
        ans+=a[i+n];
        addE(i+n,t,a[i+n]);
    }
    int qs=rd();
    while(qs--){
        int u,v;
        u=rd();
        v=rd();
        addE(u,v,inf);
    }
    ans-=dinic();
    printf("%d
",ans);
    return ;
}
int main(){
//    ios::sync_with_stdio(false);cin.tie(0);
    while(scanf("%d%d",&n,&m)!=EOF){
        solve();
    }
    return 0;
}