import java.util.Scanner;

public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int [][] a = new int[3][105];
		int []presum = new int[105];
		int []sufsum = new int[105];
		for(int i = 1; i <= n; i++) a[1][i] = sc.nextInt();
		for(int i = 1; i <= n; i++) a[2][i] = sc.nextInt();
		for(int i = 1; i <= n; i++) presum[i] = presum[i-1] + a[1][i];
		for(int i = n; i >= 1; i--) sufsum[i] = sufsum[i+1] + a[2][i];
		int ans = 0;
		for(int i = 1; i <= n; i++)
			ans = Math.max(ans, presum[i]+sufsum[i]);
		System.out.println(ans);
	}
} import java.util.Scanner; Scanner java.util public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int [][] a = new int[3][105];
		int []presum = new int[105];
		int []sufsum = new int[105];
		for(int i = 1; i <= n; i++) a[1][i] = sc.nextInt();
		for(int i = 1; i <= n; i++) a[2][i] = sc.nextInt();
		for(int i = 1; i <= n; i++) presum[i] = presum[i-1] + a[1][i];
		for(int i = n; i >= 1; i--) sufsum[i] = sufsum[i+1] + a[2][i];
		int ans = 0;
		for(int i = 1; i <= n; i++)
			ans = Math.max(ans, presum[i]+sufsum[i]);
		System.out.println(ans);
	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int [][] a = new int[3][105];
		int []presum = new int[105];
		int []sufsum = new int[105];
		for(int i = 1; i <= n; i++) a[1][i] = sc.nextInt();
		for(int i = 1; i <= n; i++) a[2][i] = sc.nextInt();
		for(int i = 1; i <= n; i++) presum[i] = presum[i-1] + a[1][i];
		for(int i = n; i >= 1; i--) sufsum[i] = sufsum[i+1] + a[2][i];
		int ans = 0;
		for(int i = 1; i <= n; i++)
			ans = Math.max(ans, presum[i]+sufsum[i]);
		System.out.println(ans);
	} main {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int [][] a = new int[3][105];
		int []presum = new int[105];
		int []sufsum = new int[105];
		for(int i = 1; i <= n; i++) a[1][i] = sc.nextInt();
		for(int i = 1; i <= n; i++) a[2][i] = sc.nextInt();
		for(int i = 1; i <= n; i++) presum[i] = presum[i-1] + a[1][i];
		for(int i = n; i >= 1; i--) sufsum[i] = sufsum[i+1] + a[2][i];
		int ans = 0;
		for(int i = 1; i <= n; i++)
			ans = Math.max(ans, presum[i]+sufsum[i]);
		System.out.println(ans);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int [][] a = new int[3][105]; a new int[3][105] 3 105 int []presum = new int[105]; presum new int[105] 105 int []sufsum = new int[105]; sufsum new int[105] 105 for(int i = 1; i <= n; i++) a[1][i] = sc.nextInt(); int i = 1; int i = 1; i 1 i <= n i n i++ i++ i a[1][i] = sc.nextInt(); a[1][i] = sc.nextInt() a[1][i] a[1] a 1 i sc.nextInt() sc.nextInt sc for(int i = 1; i <= n; i++) a[2][i] = sc.nextInt(); int i = 1; int i = 1; i 1 i <= n i n i++ i++ i a[2][i] = sc.nextInt(); a[2][i] = sc.nextInt() a[2][i] a[2] a 2 i sc.nextInt() sc.nextInt sc for(int i = 1; i <= n; i++) presum[i] = presum[i-1] + a[1][i]; int i = 1; int i = 1; i 1 i <= n i n i++ i++ i presum[i] = presum[i-1] + a[1][i]; presum[i] = presum[i-1] + a[1][i] presum[i] presum i presum[i-1] + a[1][i] presum[i-1] presum i-1 i 1 a[1][i] a[1] a 1 i for(int i = n; i >= 1; i--) sufsum[i] = sufsum[i+1] + a[2][i]; int i = n; int i = n; i n i >= 1 i 1 i-- i-- i sufsum[i] = sufsum[i+1] + a[2][i]; sufsum[i] = sufsum[i+1] + a[2][i] sufsum[i] sufsum i sufsum[i+1] + a[2][i] sufsum[i+1] sufsum i+1 i 1 a[2][i] a[2] a 2 i int ans = 0; ans 0 for(int i = 1; i <= n; i++)
			ans = Math.max(ans, presum[i]+sufsum[i]); int i = 1; int i = 1; i 1 i <= n i n i++ i++ i ans = Math.max(ans, presum[i]+sufsum[i]); ans = Math.max(ans, presum[i]+sufsum[i]) ans Math.max(ans, presum[i]+sufsum[i]) Math.max Math ans presum[i]+sufsum[i] presum[i] presum i sufsum[i] sufsum i System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int [][] a = new int[3][105];
		int []presum = new int[105];
		int []sufsum = new int[105];
		for(int i = 1; i <= n; i++) a[1][i] = sc.nextInt();
		for(int i = 1; i <= n; i++) a[2][i] = sc.nextInt();
		for(int i = 1; i <= n; i++) presum[i] = presum[i-1] + a[1][i];
		for(int i = n; i >= 1; i--) sufsum[i] = sufsum[i+1] + a[2][i];
		int ans = 0;
		for(int i = 1; i <= n; i++)
			ans = Math.max(ans, presum[i]+sufsum[i]);
		System.out.println(ans);
	}
} public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int [][] a = new int[3][105];
		int []presum = new int[105];
		int []sufsum = new int[105];
		for(int i = 1; i <= n; i++) a[1][i] = sc.nextInt();
		for(int i = 1; i <= n; i++) a[2][i] = sc.nextInt();
		for(int i = 1; i <= n; i++) presum[i] = presum[i-1] + a[1][i];
		for(int i = n; i >= 1; i--) sufsum[i] = sufsum[i+1] + a[2][i];
		int ans = 0;
		for(int i = 1; i <= n; i++)
			ans = Math.max(ans, presum[i]+sufsum[i]);
		System.out.println(ans);
	}
} Main
import java.util.Scanner;

public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int [][] a = new int[3][105];
		int []presum = new int[105];
		int []sufsum = new int[105];
		for(int i = 1; i <= n; i++) a[1][i] = sc.nextInt();
		for(int i = 1; i <= n; i++) a[2][i] = sc.nextInt();
		for(int i = 1; i <= n; i++) presum[i] = presum[i-1] + a[1][i];
		for(int i = n; i >= 1; i--) sufsum[i] = sufsum[i+1] + a[2][i];
		int ans = 0;
		for(int i = 1; i <= n; i++)
			ans = Math.max(ans, presum[i]+sufsum[i]);
		System.out.println(ans);
	}
}
