UVA11389 The Bus Driver Problem

//Serene
#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdlib>
#include<cstdio>
#include<cmath>
using namespace std;
const int maxn=100+10;
int n,d,r,ans,aft[maxn],nig[maxn];

int aa;char cc;
int read() {
	aa=0;cc=getchar();
	while(cc<‘0‘||cc>‘9‘) cc=getchar();
	while(cc>=‘0‘&&cc<=‘9‘) aa=aa*10+cc-‘0‘,cc=getchar();
	return aa;
}

int main() {
	n=read();d=read();r=read();
	while(n) {
		ans=0;
		for(int i=1;i<=n;++i) aft[i]=read();
		for(int i=1;i<=n;++i) nig[i]=read();
		sort(aft+1,aft+n+1);sort(nig+1,nig+n+1);
		for(int i=1;i<=n;++i) if(aft[i]+nig[n-i+1]>d) ans+=(aft[i]+nig[n-i+1]-d);
		printf("%d\n",ans*r);
		n=read();d=read();r=read();
	}
	return 0;
}