#include<iostream>

#include<cstdio>

#include<algorithm>

#include<cstring>

#define N 25009

#define LL long long

using namespace std;

int n,x,y;

LL ans;

int a[N],b[N];

int main(){

    scanf("%d%d%d",&n,&x,&y);

    for(int i=;i<=n;i++)scanf("%d%d",&a[i],&b[i]);

    sort(a+,a+n+);sort(b+,b+n+);

    for(int i=;i<=n;i++){

        if(a[i]==b[i])continue;

        if(a[i]>b[i])ans+=y*(a[i]-b[i]);

        if(b[i]>a[i])ans+=x*(b[i]-a[i]);

    }

    cout<<ans<<endl;

    return ;

}