#include <iostream>

 #include <cstdio>

 #include <algorithm>

 using namespace std;

 const int maxn = ;

 int n,m,money,fa[maxn];//n朵云,m个搭配,w现有钱的数目

 int qwqw[maxn],f[maxn],qwqc[maxn],w[maxn],c[maxn];

 int find(int x)

 {

     return x==fa[x]?x:fa[x]=find(fa[x]);

 }

 int unionn(int x, int y)

 {

 }

 int main()

 {

     scanf("%d%d%d",&n,&m,&money);

     for(int i = ; i <= n; i++)

     fa[i] = i;

     for(int i = ; i <= n; i++)

     {

         int fee,d;

         scanf("%d%d",&fee,&d);

         w[i] = fee; c[i] = d;

     }

     for(int i = ; i <= m; i++)

     {

         int u,v;

         scanf("%d%d",&u,&v);

         int x = find(u);

         int y = find(v);

         if(x!=y)

         fa[y] = x;

     }

     for(int i = ; i <= n; i++)

     {

         if(fa[i]!=i)

         {

             c[find(i)] += c[i];

             w[find(i)] += w[i];

             c[i] = ; w[i] = ;

         }

     }

     for(int i = ; i <= n; i++)

         for(int v = money; v >= w[i]; v--)

         f[v] = max(f[v],f[v-w[i]]+c[i]);

     printf("%d",f[money]);

     return ;

 }