题解 100% AC

#include <bits/stdc++.h>
using namespace std;
int main(){
    int n,m,a,q,b[10010],minb=2147483647;cin>>n>>m>>a>>q;
    for(int i=1;i<=q;i++){
    	cin>>b[i];
        minb=min(b[i],minb);
    }
    cout<<(n*m)-a*m-minb*n+a*minb;
	return 0;
}