#include <iostream>
#include <cmath>
#include <cstring>
using namespace std;

long long w[1000010],v[1000010],n,m,S,res,s1[1000010],s2[1000010],l[1000010],r[1000010];
long long calc(int x)
{
	cerr<<x<<endl;
	memset(s1,0,sizeof(s1)),memset(s2,0,sizeof(s2));
	for(int i=1;i<=n;i++)
	{
		s1[i]=s1[i-1],s2[i]=s2[i-1];
		if(w[i]>=x)s1[i]++,s2[i]+=v[i];
	}
	for(int i=1;i<=m;i++)
	{
		res+=(s1[r[i]]-s1[l[i]-1])*(s2[r[i]]-s2[l[i]-1]);
	}
	return res;
}
int main()
{
        ios::sync_with_stdio(false);
	cin>>n>>m>>S;
	for(int i=1;i<=n;i++)
	{
		cin>>w[i]>>v[i];
	}
	for(int i=1;i<=m;i++)
	{
		cin>>l[i]>>r[i];
	}
	long long l=0,r=1e6,ans=0x3f3f3f3f3f3f3f3f;
	while(l<=r)
	{
		long long mid=(l+r)/2;
		if(abs(calc(mid)-S)<ans)ans=abs(res-S);
		if(res<S)r=mid-1;
		else l=mid+1;
		res=0;
	}
	cout<<ans<<endl;
	return 0;
}