#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define llu unsigned long long
#define ld double
#define llu unsigned long long
#define rep(i,x,y)  for(int i=int(x);i<int(y);++i)
#define For(i,x,y)  for(int i=int(x);i<=int(y);++i)
#define FOr(i,x,y)  for(int i=int(x);i>=int(y);--i)
#define pi acos(-1) 
#define mk make_pair
#define pa pair<ll,ll>
#define lf else if
#define IL inline
#define max(x,y)    ((x)<(y)?(y):(x))
#define min(x,y)    ((x)<(y)?(x):(y))
#define sqr(x)      ((x)*(x))
#define Mul(x,y)    ((x)=1LL*(x)*(y)%mod)
#define Add(x,y)    ((x)=((x)+(y))%mod)
#define Max(x,y)    ((x)=((x)<(y)?(y):(x)))
#define Min(x,y)    ((x)=((x)>(y)?(y):(x)))
#define E(x)        return writeln(x),0
#define LL			(long long)
#define p(x)        printf("~%lld~\n",LL(x))
#define pp(x,y)     printf("~~%lld %lld~~\n",LL(x),LL(y))
#define ppp(x,y,z)  printf("~~~%lld %lld %lld~~~\n",LL(x),LL(y),LL(z))
#define pppp(a,b,c,d)	printf("~~~%lld %lld %lld %lld\n",LL(a),LL(b),LL(c),LL(d))
#define f_in(x)     freopen(x".in","r",stdin)
#define f_out(x)    freopen(x".out","w",stdout)
#define open(x)     f_in(x),f_out(x)
#define fi first
#define se second
#define GuYue		puts("\nGuYueNa________________________________________________________________________________")
typedef complex<double> E;
namespace cqz{
#ifdef LOCAL
    struct _{_(){freopen("cf.in","r",stdin);}}_; 
#endif 
#define NEG 1
    static const int GYN=2333333;
    char SZB[GYN],*S=SZB,*T=SZB;
    inline char gc(){   if (S==T){  T=(S=SZB)+fread(SZB,1,GYN,stdin); if (S==T) return '\n';  }   return *S++;    }
#if NEG
    inline ll read(){    ll x=0,g=1; char ch=gc();   for (;!isdigit(ch);ch=gc()) if (ch=='-') g=-1;  for (;isdigit(ch);ch=gc())  x=x*10-48+ch;   return x*g; }
    inline void write(ll x){    if (x<0) putchar('-'),x=-x;  if (x>=10)   write(x/10);    putchar(x%10+'0');  }
#else
    inline ll read(){    ll x=0; char ch=gc();   for (;!isdigit(ch);ch=gc());    for (;isdigit(ch);ch=gc())  x=x*10-48+ch;   return x;   }
    inline void write(ll x){    if (x>=10)   write(x/10);    putchar(x%10+'0');  }
#endif
    inline char readchar(){ char ch=gc();   for(;isspace(ch);ch=gc());  return ch;  }
    inline ll readstr(char *s){ char ch=gc();   int cur=0;  for(;isspace(ch);ch=gc());      for(;!isspace(ch);ch=gc())  s[cur++]=ch;    s[cur]='\0';    return cur; }
	void Print(long long *a,int s,int t){For(i,s,t)printf("%lld ",a[i]);}
	void Print(int *a,int s,int t){For(i,s,t)printf("%d ",a[i]);}
	void Print(char *a,int s,int t){For(i,s,t)putchar(a[i]);}
	void writeln(ll x){write(x);puts("");}
}using namespace cqz;
const ll N=3000010,inf=1e18;
ll m,n,fa[N],a[N],b[N],vis[N],sum[N],ans[N],cur[N];
vector<ll>g[N];
struct dt{ll a,b,id;}p[N];
bool cmp(dt a,dt b){return a.a<b.a;}
ll find(ll x){return x==fa[x]?x:fa[x]=find(fa[x]);}
int main(){
	n=read();m=read();
	For(i,1,n){a[i]=read(),b[i]=read();a[i]=max(a[i],b[i]);p[i]=(dt){a[i],b[i],i};sum[i]=b[i];}
	For(i,1,m){ll x=read(),y=read();g[x].push_back(y);g[y].push_back(x);}
	sort(p+1,p+n+1,cmp);
	For(i,1,n)fa[i]=i,ans[i]=inf;
	for(ll i=1,j;i<=n;i=j+1){
		j=i;for(;p[j+1].a==p[i].a;++j);
		For(k,i,j)vis[p[k].id]=1;
		For(k,i,j){
			ll x=p[k].id;
			rep(edge,0,g[x].size()){
				ll to=find(g[x][edge]);
				if (!vis[to])continue;
				cur[g[x][edge]]=to;
			}
		}
		For(k,i,j){
			ll x=p[k].id;
			rep(edge,0,g[x].size()){
				ll to=find(g[x][edge]);
				if (!vis[to]||find(x)==to)continue;
				fa[find(to)]=find(x);
				sum[find(x)]+=sum[to];
			}
		}
		For(k,i,j){
			ll x=p[k].id;
			rep(edge,0,g[x].size()){
				ll to=cur[g[x][edge]];
				if (!vis[to]||vis[to]==i)continue;
				ll now=find(x);
				ll cost=max(a[x],ans[to]+b[x])+sum[now]-sum[to]-b[x];
				Min(ans[now],cost);
			}
			Min(ans[find(x)],a[find(x)]+sum[find(x)]-b[x]);
		} 
	}writeln(ans[find(1)]);
}

Measured memory_bytes: 99968