#include <stdio.h>
#include <math.h>

int main(void) {
	int x,n;
	int p[110];
	int np[110];
	int i,j;
	int flag = 0;
	int ans;
	
	for(i=0;i<101;i++){
		np[i]=i;
	}
	
	scanf("%d",&x);
	//printf("%d\n",x);
	scanf("%d",&n);
	//printf("%d\n",n);
	for(i=1;i<n+1;i++){
		scanf("%d",&p[i]);
		np[p[i]] = -5;
		//printf("%d %d\n",p[i], np[p[i]]);
	}
	
	for(i=1;i<101;i++){
		if(np[i] == x){
			ans = x;
			flag = 1;
		}
	}
	
	if(flag == 0){
		for(i=1;i<101;i++){
			if(np[x+i] == -5 && np[x-i]==-5){
				//printf("NG");
			}
			else if(np[x-i] == -5){
				ans = np[x+i];
				break;
			}
			else {
				ans = np[x-i];
				break;
			}
		}
	}
	
	printf("%d",ans);
	printf("\n");	
	return 0;
}
