#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
int m[100005];
int b[100005];
int main(void){
	int n,x,y,s=0;
	cin>>n>>x>>y;
	for(int i=0;i<n;i++){
		cin>>m[i]>>b[i];
	}
	sort(m,m+n);
	sort(b,b+n);
	for(int i=0;i<n;i++){
		if(m[i]>b[i]){
			s+=(m[i]-b[i])*y;
		}else{
			s+=(b[i]-m[i])*x;
		}
	}
	cout<<s;
	return 0;
}