import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int a = in.nextInt();
        int b = in.nextInt();
        String n = in.nextLine();
        String str1 = in.nextLine();
        String str2 = in.nextLine();
        String[] strArray1 = str1.split(" ");
        String[] strArray2 = str2.split(" ");
        int[] intArray1 = new int[strArray1.length];
        int[] intArray2 = new int[strArray2.length];
        for(int i = 0 ; i < strArray1.length; i++){
            intArray1[i] = Integer.parseInt(strArray1[i]);
        }
        for(int i = 0 ; i < strArray2.length; i++){
            intArray2[i] = Integer.parseInt(strArray2[i]);
        }
        int res = 0;
        for(int i = 0; i < strArray1.length; i++){
            res += Math.min(intArray1[i], intArray2[i]);
        }
        res = Math.min(res, b);
        System.out.println(res);
    }
}