#include <bits/stdc++.h>

FILE *in = fopen("tribute.in", "r"), *out = fopen("tribute.out", "w") ;

int ox[50005] ;
int oy[50005] ;

int main() {
        int n, dx, dy, i, x, y ;
        fscanf(in, "%d %d %d", &n, &dx, &dy) ;
        for (i = 1 ; i <= n ; ++ i) {
                fscanf(in, "%d %d", &x, &y) ;
                ox[i] = x ;
                oy[i] = y ;
        }
        int ans(0) ;
        std::sort(ox + 1, ox + 1 + n) ;
        std::sort(oy + 1, oy + 1 + n) ;
        for (i = 1 ; i <= n ; ++ i) {
                ans += std::max(0, ox[i + 1] - ox[n - i] - dx) ;
                ans += std::max(0, oy[i + 1] - oy[n - i] - dy) ;
        }
        fprintf(out, "%d", ans) ;
}