#include <stdio.h>
#include <stdlib.h>
int main(void){
    // Your code here!
    int x, n, mini=100, kouhobig,big,small, kouhomin, onazi=0;
    int p[101];
    scanf("%d%d", &x, &n);
    kouhobig = x;
    kouhomin = x;
    if(n!=0){
    for(int i = 0; i<n; i++){
        scanf("%d", &p[i]);
    }
    }
    else {
        printf("%d", x);
    }
    
    if(n!=0){
  for(int j = 0; j<n; j++){
      if(mini>abs(p[j]-x)){
          mini = abs(p[j]-x);
      if(x == p[j]){
          onazi = 1;
      }
      }
  }
    }
    
    kouhobig = x+mini;
    kouhomin = x-mini;
    big = x+1;
    small = x-1;
        
        for(int l = 0; l < 65535; l++){
            for(int m = 0;m<n;m++){
                if(p[m] =! kouhobig+m && big>kouhobig+m){
                    big = kouhobig+m;
                }
                if(p[m] =! kouhomin-m && small<kouhomin-m){
                    small = kouhomin-m;
                }
            }
        }
        
    if(n!=0){
    if(big+small == 0){
        printf("%d", small);
    }
    else if(abs(big-x)<abs(small-x)){
        printf("%d", big);
    }
    else if(abs(big-x)>abs(small-x)){
        printf("%d", small);
    }
    }
    return 0;
    
}