CTNEWS - Lâu đài cát
Tác giả: happyboy99x
Ngôn ngữ: C++
#include <algorithm>
#include <bitset>
#include <cctype>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>
using namespace std;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef vector<vii> vvii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef long long LL;
#define sz(a) (int((a).size()))
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define all(c) (c).begin(), (c).end()
#define tr(c,i) for(typeof((c).begin()) i = (c).begin(), _e = (c).end(); i != _e; ++i)
#define present(c,x) ((c).find(x) != (c).end())
#define cpresent(c,x) (find(all(c),x) != (c).end())
#define rep(i,n) for(int i = 0, _n = (n); i < _n; ++i)
#define repd(i,n) for(int i = (n)-1; i >= 0; --i )
#define fo(i,a,b) for(int i = (a), _b = (b); i <= _b; ++i)
#define fod(i,a,b) for(int i = (a), _b = (b); i >= _b; --i)
#define INF 1000000000
#define N 25000+5
int a[N], b[N], n;
LL x, y;
int main() {
scanf("%d%lld%lld", &n, &x, &y);
rep(i,n) scanf("%d%d",a+i,b+i);
sort(a,a+n); sort(b,b+n);
LL res = 0;
rep(i,n)
if(a[i] > b[i]) res += y*(a[i]-b[i]);
else res += x*(b[i]-a[i]);
printf("%lld\n", res);
return 0;
}