#include<bits/stdc++.h>
using namespace std;
#define ioio ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define endl "\n"
#define debug(x) cout<<#x<<":"<<x<<endl;
#define L(k) k<<1
#define R(k) k<<1|1
#define P pair
#define P1 first
#define P2 second
#define u_map unordered_map
#define p_queue priority_queue
typedef long long ll;
const double eps = 1e-6;
const int mod = 1e9 + 7;
const int INF = 0x3f3f3f3f;
const int INF2 = (1 << 31);
const int N = 1e6 + 7;
int dx[] = {0, 0, 1, -1}, dy[] = {1, -1, 0, 0};
/*-------------------------------------------------*/

int n,m,w;
struct st{
	int c,d;
}pre[N];
int dp[N];
vector<st>V;
int fa[N];


void init(int n){
	for(int i=1;i<=n;i++)
		fa[i]=i;
}
int fin(int x){
	if(x!=fa[x])
		fa[x]=fin(fa[x]);
	return fa[x];
}
void mer(int x,int y){
	x=fin(x),y=fin(y);
	fa[x]=y;
}
int main(){
	ioio
	cin>>n>>m>>w;
	init(n);
	int c,d;
	for(int i=1;i<=n;i++){
		cin>>c>>d;
		pre[i].c=c,pre[i].d=d;
	}
	int u,v;
	while(m--){
		cin>>u>>v;
		mer(u,v);
	}
	for(int i=1;i<=n;i++)
		if(i!=fa[i]){
			int f=fin(i);
			pre[f].c+=pre[i].c;
			pre[f].d+=pre[i].d;
		}
	for(int i=1;i<=n;i++)
		if(i==fa[i])
			V.push_back({pre[i].c,pre[i].d});
	cout<<endl;
	int len=V.size();
	for(int i=1;i<=len;i++)
		for(int j=w;j>=V[i-1].c;j--)
			dp[j]=max(dp[j],dp[j-V[i-1].c]+V[i-1].d);
	cout<<dp[w]<<endl;
	return 0;
}