#include<bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10;
int a[N],b[N];
int main()
{
	int n,x,y;
	cin >> n >> x >> y;
	for(int i = 1;i <= n;i++)
	{
		cin >> a[i] >> b[i];
	}
	sort(a,a + n);
	sort(b,b + n);
	int ans = 0;
	for(int i = 1;i <= n;i++)
	{
		if(a[i] > b[i])
		{
			ans += (a[i] - b[i]) * y;
		}
		else
		{
			ans += (b[i] - a[i]) * x;
		} 		
	}
	cout << ans; 
	return 0;
}