#include<bits/stdc++.h>
#define ll long long
#define N 200000
using namespace std;
inline ll read(){
	ll x=0,f=1;char ch=getchar();
	while(!isdigit(ch)){if(ch=='-') f=-1;	ch=getchar();}
	while(isdigit(ch)){x=(x<<3)+(x<<1)+(ch^48);ch=getchar();}
	return f*x;
}
ll n=read(),m=read(),s=read(),w[N],v[N],l[N],r[N],s1[N],sum[N],ans=10e18,maxn=0;
bool check(ll x){
	memset(sum,0,sizeof(sum));
	memset(s1,0,sizeof(s1));
	ll y=0;
	for(int i=1;i<=n;i++){
		s1[i]=s1[i-1];
		sum[i]=sum[i-1];
		if(w[i]>=x) {
			sum[i]++;
			s1[i]+=v[i];
		}
	}
	for(int i=1;i<=m;i++)	y+=(sum[r[i]]-sum[l[i]-1])*(s1[r[i]]-s1[l[i]-1]);
	maxn=(ll)abs(s-y);
	if(y>s) return true;
	return false;
}
int main(){
	for(int i=1;i<=n;i++) w[i]=read(),v[i]=read();
	for(int i=1;i<=m;i++) l[i]=read(),r[i]=read();
	ll x=0,y=10e18;
	while(x<=y)
	{
		ll mid=x+y>>1;
		if(check(mid)) x=mid+1;
		else y=mid-1;
		if(maxn<ans) ans=maxn;
	}
	printf("%lld",ans);
	return 0;	
}