#include<iostream>
#include<cstdio>
#include<string>
#include<algorithm>
#include<cmath>
#define mod 1000000007
#define ll long long
#define inf (1LL<<60)
using namespace std;
int n,m,mx=-1;
int l[200005],r[200005];
int w[200005],v[200005];
ll s,ans=inf;
ll sum[200005],cnt[200005];
/*ll read()
{
    ll x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}*/
ll cal(int W){
	ll tmp=0;
	for(int i=1;i<=n;i++){
		sum[i]=sum[i-1];
		cnt[i]=cnt[i-1];
		if(w[i]>=W){
			sum[i]+=v[i];
			cnt[i]++;
		}
	}
	for(int i=1;i<=m;i++){
		tmp+=(cnt[r[i]]-cnt[l[i]-1])*(sum[r[i]]-sum[l[i]-1]);
	}
	return tmp;
}
int main()
{
	freopen("qc.in","r",stdin);
	freopen("qc.out","w",stdout); 
	scanf("%d%d%lld",&n,&m,&s);
	for(int i=1;i<=n;i++){
		scanf("%d%d",&w[i],&v[i]);
	}
	for(int i=1;i<=n;i++)
		mx=max(mx,w[i]);
	for(int i=1;i<=m;i++){
		scanf("%d%d",&l[i],&r[i]);
	}
	int l=0,r=mx+1;
	while(l<=r){
		int mid=(l+r)>>1;
		ll t=cal(mid);
		ans=min(ans,abs(t-s));
		if(t<s)r=mid-1;
		else l=mid+1;
	}
	printf("%lld\n",ans);
	return 0;
}