#include<bits/stdc++.h>
using namespace std;
int n,m;
long long s,mid,sum,ans,W,maxw=-1,minw=100000000,minn=100000000;
long long w[200100],v[200100],l[200100],r[200100],prv[200100],prw[200100];
int main()
{
	cin>>n>>m>>s;
	for(int i=1;i<=n;i++)
	{
		cin>>w[i]>>v[i];
		maxw=max(maxw,w[i]);
		minw=min(minw,w[i]);
	}
	for(int i=1;i<=m;i++)
	{
		cin>>l[i]>>r[i];
	}
	while(minw<=maxw)
	{
		mid=(minw+maxw)/2;
		ans=0;
		for(int i=1;i<=n;i++)
		{
			if(w[i]>mid)
			{
				prw[i]=prw[i-1]+1;
				prv[i]=prv[i-1]+v[i];
			}
			else
			{
				prw[i]=prw[i-1];
				prv[i]=prv[i-1];
			}
		}
		for(int i=1;i<=m;i++)
		{
			sum+=(prw[r[i]]-prw[l[i]-1])*(prv[r[i]]-prv[l[i]-1]);
		}
		ans=s-sum;
		if(ans)
		{
			maxw=mid-1;
		}
		else
		{
			minw=mid+1; 
		}
		minn=min(minn,abs(ans));
	}
	cout<<minn;
	return 0;
}