#include <stdio.h>
#include <stdlib.h>

int main(void){
    
    int x,n;
    scanf("%d %d",&x,&n);
    
    int p[101]={0};
    
    for(int i=1;i<=n;i++){
    scanf("%d",&p[i]);
    }
    int tmp;
    
    for (int i=1; i<=n; ++i) {
        for (int j=i+1; j<=n; ++j) {
              if (p[i] > p[j]) {
               tmp =  p[i];
              p[i] = p[j];
              p[j] = tmp;
             }
        }
    }
    
    for (int i=1; i<=n; i++) {
        if(x<p[i]){
        printf("%d",x);
        return 0;
        }
        
        if(x==p[i]){
            for(int j=1;j<i;j++){
             if(p[i-j]!=x-j){
                printf("%d",x-j);
                return 0;
             }   
             if(p[i+j]!=x+j){
                printf("%d",x+j);
                return 0;
             }     
            }
                printf("%d",x-i);
                return 0;
        }
    }
    
    printf("%d",x);
    return 0;
}