런타임오류가 나는데 코드 확인 부탁드리겠습니다.

import java.util.Scanner;

public class Main {
	static Scanner sc = new Scanner(System.in);
		
	public static void main(String[] args) {		
		int n = sc.nextInt();
		int[] arr1 = new int[n];
		for(int i=0; i<n; i++) {
			arr1[i] = sc.nextInt();
		}
		
		int m = sc.nextInt();
		int[] arr2 = new int[m];
		for(int i=0; i<m; i++) {
			arr2[i] = sc.nextInt();
		}
		
		for(int x : solution(arr1, arr2, n,m))
				System.out.print(x + " ");
		
	}
	
	static int[] solution(int[] arr1, int[] arr2, int n, int m) {
		int[] answer = new int[n+m];
		int a=0,b=0,c=0;
		while(c<n+m) {
		if(a<n && b<m && arr1[a]<=arr2[b]) {
			answer[c] = arr1[a];
			a++; c++;
		}
		else if(a<n && b<m && arr1[a]>arr2[b]){
			answer[c] = arr2[b];
			b++; c++;
		}
		else if(a>=n || b>=m) {
			if(n>=m) {
					answer[c] = arr1[a];
					a++; c++;	
			}
		
			else {			
					answer[c] = arr2[b];
					b++; c++;
		}
		
		}
		}
		return answer;
		
	}
}