#include<cstdlib>
#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;

int n,m;
long long S,Y,ansy;
long long ans;
int l[200010],r[200010],w[200010],y[200010];
long long s[200010],d[200010];

long long Abs(long long x,long long y)
{
if (x>y) return (x-y);
else return (y-x);
}

void Init()
{
scanf("%d%d%I64d",&n,&m,&S);
for (int i=1;i<=n;i++) scanf("%d%d",&w[i],&y[i]);
for (int i=1;i<=m;i++) scanf("%d%d",&l[i],&r[i]);
}

void Main()
{
long long left=0,right=0,mid;
ans=100000;
ans*=100000000;
for (int i=1;i<=n;i++) 
if (w[i]>right) right=w[i];
right+=100;
while (left<right)
{
mid=(left+right)/2;
memset(s,0,sizeof(s));
memset(d,0,sizeof(d));
for (int i=1;i<=n;i++)
if (w[i]>=mid) s[i]=s[i-1]+y[i],d[i]=d[i-1]+1;
else s[i]=s[i-1],d[i]=d[i-1];
Y=0;

for (int i=1;i<=m;i++)
{
long long temp_x=s[r[i]]-s[l[i]-1];
long long temp_y=d[r[i]]-d[l[i]-1];
long long temp_z=temp_x*temp_y;  
Y+=temp_z;
}
if (Abs(Y,S)<ans) ans=Abs(Y,S);
if (Y>S) left=mid+1;
else right=mid;
}
printf("%I64d\n",ans);
}
 

int main()
{
freopen("qc.in","r",stdin);
freopen("qc.out","w",stdout);

Init();
Main();
fclose(stdin); fclose(stdout);
return 0; 
}