#include<iostream>
#include<algorithm>
#include<cmath>
using namespace std;
const long N=210000;
long w[N],v[N],L[N],R[N],n,m,wmax(0);
long long s,ans,sum[N],sv[N];
long long f(long W)
{
	
	sum[0]=0;sv[0]=0;
	for(long i=1;i<=n;i++)
	w[i]>=W?(sum[i]=sum[i-1]+1,sv[i]=sv[i-1]+v[i]):(sum[i]=sum[i-1],sv[i]=sv[i-1]);
	long long t=0;
    for(long i=1;i<=m;i++) 
			t+=(sum[R[i]]-sum[L[i]-1])*(sv[R[i]]-sv[L[i]-1]);
	return t;
			
}
void solve()
{
	long low,high,mid;
	long long now;
	ans=0x7fffffffffffffffll;
	for(low=0,high=wmax;low<=high;)
	{
		mid=(low+high)/2;
		now=f(mid);
		if (abs(now-s)<ans) ans=abs(now-s);
		if(now==s) return;
		if (now<s) high=mid-1;
		else low=mid+1;
	}
}
void input()
{
	cin>>n>>m>>s;	
	for(long i=1;i<=n;i++)	
	{
		cin>>w[i]>>v[i];
		if (w[i]>wmax) wmax=w[i];
	}
	for(long i=1;i<=m;i++)	cin>>L[i]>>R[i];
} 
int main()
{
	input();
    solve();
	cout<<ans<<endl;	
	
	return 0;
}

/**************************************************************
	Problem: 2308
	User: admin
	Language: C++
	Result: Accepted
	Time:876 ms
	Memory:11916 kb
****************************************************************/