#include<bits/stdc++.h>
#define int long long
#define N 200005
#define mid ((l+r)>>1)
#define ls (u<<1)
#define rs (u<<1|1)
#define lson ls,l,mid
#define rson rs,mid+1,r
using namespace std;

struct Node
{
	int num;
	int sum;
}T[N<<2];

int n,m,s,d=0xFFFFFFFFFFFFFFF,L,R=N>>1,w[N],v[N],l[N],r[N]; 

inline void push_up(int u)
{
	T[u].num=T[ls].num+T[rs].num;
	T[u].sum=T[ls].sum+T[rs].sum;
}

void build(int u,int l,int r,int W)
{
	if(l==r)
	{
		T[u].num=w[l]>=W?1:0;
		T[u].sum=T[u].num*v[l];
		return;
	}
	build(lson,W);
	build(rson,W);
	push_up(u);
}

int query_num(int u,int l,int r,int x,int y)
{
	if(x<=l&&r<=y)	return T[u].num;
	int res=0;
	if(x<=mid)	res+=query_num(lson,x,y);
	if(y>mid)	res+=query_num(rson,x,y);
	return res;
}

int query_sum(int u,int l,int r,int x,int y)
{
	if(x<=l&&r<=y)	return T[u].sum;
	int res=0;
	if(x<=mid)	res+=query_sum(lson,x,y);
	if(y>mid)	res+=query_sum(rson,x,y);
	return res;
}

int y(int W)
{
	int res=0;
	build(1,1,n,W);
	for(int i=1;i<=m;i++)
		res+=query_num(1,1,n,l[i],r[i])*query_sum(1,1,n,l[i],r[i]);
	return res;
}

signed main()
{
	scanf("%lld%lld%lld",&n,&m,&s);
	for(int i=1;i<=n;i++)	scanf("%lld%lld",&w[i],&v[i]);
	for(int i=1;i<=m;i++)	scanf("%lld%lld",&l[i],&r[i]);
	while(L<=R)
	{
		int M=(L+R)>>1,sumy=y(M);
		if(d>abs(s-sumy))	d=abs(s-sumy);
		if(sumy<s)	R=M-1;
		if(sumy>s)	L=M+1;
		if(sumy==s)	break;
	}
	printf("%lld",d);
	return 0;
}