#include<bits/stdc++.h>

using namespace std;

inline int read(){

   	int s=0;

   	int w=1;

   	char ch=getchar();

   	for(;ch<'0'||ch>'9';ch=getchar())

    	if(ch=='-')

			w=-1;

   	for(;ch>='0'&&ch<='9';ch=getchar())

		s=s*10+ch-'0';

   	return s*w;

}

void write(int x) {

	if(x<0){

    	putchar('-');

    	x=-x;

  	}

  	if(x>9)

    	write(x/10);

	putchar(x%10+'0');

	return;

}

int n,m,s;

int ans=1145141919;

struct node{
	
	int w;
	
	int v;
	
}a[200086];

int l[200086];

int r[200086];

int sum1[200086];

int sum2[200086];

void ssum(int W){
	
	if(a[1].w>=W){
	
		sum1[1]=1;

		sum2[1]=a[1].v;
		
	}
    
	for(int i=2;i<=n;i++)
    
	    if(a[i].w>=W){
    
	        sum1[i]=sum1[i-1]+1;
    
	        sum2[i]=sum2[i-1]+a[i].v;
    
	    }
    
	    else{
    
	        sum1[i]=sum1[i-1];
    
	        sum2[i]=sum2[i-1];
    
		}

}//前缀和 

int f(int W){
	
	ssum(W);
	
	int sum=0;
	
	for(int i=1;i<=m;i++)
			
		sum+=(sum1[r[i]]-sum1[l[i]-1])*(sum2[r[i]]-sum2[l[i]-1]);
		
//	cout<<sum<<"\n\n";
		
	return sum;
	
}//同check函数 

int main(){

	n=read();
	
	m=read();
	
	s=read();

	for(int i=1;i<=n;i++){
		
		a[i].w=read();
		
		a[i].v=read();
		
	}
	
	for(int i=1;i<=m;i++){
		
		l[i]=read();
		
		r[i]=read(); 
		
	}
	
	int ll=1;
		
	int rr=n;
		
	int mid=0;	
		
	while(ll<=rr){
		
		mid=(ll+rr)/2;
        
		ans=min(ans,abs(f(mid)-s));//去最接近的值 
        
		if(f(mid)>s)
        
		    ll=mid+1;
        
		else
        
		    rr=mid-1;

//		cout<<mid<<"    "<<ans<<"\n\n";
			
	}//二分 
		
//	}

//	cout<<mid<<"    "<<ans<<"\n\n";

	write(ans);

	return 0;
	
}

样例能过，悬2关