#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll n,m,s;
ll rid,mid;
ll lef=0x3f3f3f3f3f3f3f3f;
ll cnt;
ll w[200005],v[200005];
ll a[200005],b[200005];  
ll now,cmp;	
ll sum[200005];
ll g[200005];
ll minn=0x3f3f3f3f3f3f3f3f;
bool check(int x)
{
	now=0; cmp=0;
	memset(sum,0,sizeof(sum)); memset(g,0,sizeof(g));
	for(int i=1;i<=n;i++)
	{
		if(w[i]>=x)
		{
			sum[i]=v[i]+sum[i-1]; g[i]=g[i-1]+1;
		}
		else 
		{
			sum[i]=sum[i-1]; g[i]=g[i-1];
		}
	}
	for(int i=1;i<=m;i++)
	{
		cmp+=(sum[b[i]]-sum[a[i]-1])*(g[b[i]]-g[a[i]-1]);
	}
	now=llabs(cmp-s);
	if(cmp>s) return true;
	else return false;	
}
int main()
{
	cin>>n>>m>>s;
	for(int i=1;i<=n;i++)
	{
		cin>>w[i]>>v[i];
		rid=max(rid,w[i]);
		lef=min(lef,w[i]);
	}
	for(int i=1;i<=m;i++)
	{
		cin>>a[i]>>b[i];
	} 
	lef--;rid+=2;
	while(lef<=rid)
	{
		mid=(lef+rid)/2;
		if(check(mid)==true) lef=mid+1;
		else rid=mid-1;
		if(minn>now) minn=now;
	}
	printf("%lld",now);
	return 0;
}