import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.StringTokenizer;

public class Main {
	public static void main(String[] args) {
		FastScanner sc = new FastScanner(System.in);
		int x = sc.nextInt(), n = sc.nextInt();
		ArrayList<Integer> list = new ArrayList<>();
		for(; n > 0; n--) {
			list.add(sc.nextInt()-x);
		}
		Collections.sort(list);
		int ab = -100;
		for(int i  = -99; i <= 99; i++) {
			if(!list.contains(i) && Math.abs(ab) > Math.abs(i)) {
				ab = i;
			}
		}
		System.out.println(x + ab);
		
	}
	
	static class FastScanner {
		private BufferedReader reader = null;
	    private StringTokenizer tokenizer = null;
	    public FastScanner(InputStream in) {
	        reader = new BufferedReader(new InputStreamReader(in));
	        tokenizer = null;
	    }

	    public String next() {
	        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    }

	    public String nextLine() {
	        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                return reader.readLine();
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }

	        return tokenizer.nextToken("\n");
	    }

	    public long nextLong() {
	        return Long.parseLong(next());
	    }

	    public int nextInt() {
	        return Integer.parseInt(next());
	    }

	    public double nextDouble() {
	         return Double.parseDouble(next());
	     }

	    public int[] nextIntArray(int n) {
	        int[] a = new int[n];
	        for (int i = 0; i < n; i++)
	            a[i] = nextInt();
	        return a;
	    }

	    public long[] nextLongArray(int n) {
	        long[] a = new long[n];
	        for (int i = 0; i < n; i++)
	            a[i] = nextLong();
	        return a;
	    }
	}
} import java.io.BufferedReader; BufferedReader java.io import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.InputStreamReader; InputStreamReader java.io import java.util.ArrayList; ArrayList java.util import java.util.Collections; Collections java.util import java.util.StringTokenizer; StringTokenizer java.util public class Main {
	public static void main(String[] args) {
		FastScanner sc = new FastScanner(System.in);
		int x = sc.nextInt(), n = sc.nextInt();
		ArrayList<Integer> list = new ArrayList<>();
		for(; n > 0; n--) {
			list.add(sc.nextInt()-x);
		}
		Collections.sort(list);
		int ab = -100;
		for(int i  = -99; i <= 99; i++) {
			if(!list.contains(i) && Math.abs(ab) > Math.abs(i)) {
				ab = i;
			}
		}
		System.out.println(x + ab);
		
	}
	
	static class FastScanner {
		private BufferedReader reader = null;
	    private StringTokenizer tokenizer = null;
	    public FastScanner(InputStream in) {
	        reader = new BufferedReader(new InputStreamReader(in));
	        tokenizer = null;
	    }

	    public String next() {
	        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    }

	    public String nextLine() {
	        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                return reader.readLine();
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }

	        return tokenizer.nextToken("\n");
	    }

	    public long nextLong() {
	        return Long.parseLong(next());
	    }

	    public int nextInt() {
	        return Integer.parseInt(next());
	    }

	    public double nextDouble() {
	         return Double.parseDouble(next());
	     }

	    public int[] nextIntArray(int n) {
	        int[] a = new int[n];
	        for (int i = 0; i < n; i++)
	            a[i] = nextInt();
	        return a;
	    }

	    public long[] nextLongArray(int n) {
	        long[] a = new long[n];
	        for (int i = 0; i < n; i++)
	            a[i] = nextLong();
	        return a;
	    }
	}
} Main public static void main(String[] args) {
		FastScanner sc = new FastScanner(System.in);
		int x = sc.nextInt(), n = sc.nextInt();
		ArrayList<Integer> list = new ArrayList<>();
		for(; n > 0; n--) {
			list.add(sc.nextInt()-x);
		}
		Collections.sort(list);
		int ab = -100;
		for(int i  = -99; i <= 99; i++) {
			if(!list.contains(i) && Math.abs(ab) > Math.abs(i)) {
				ab = i;
			}
		}
		System.out.println(x + ab);
		
	} main {
		FastScanner sc = new FastScanner(System.in);
		int x = sc.nextInt(), n = sc.nextInt();
		ArrayList<Integer> list = new ArrayList<>();
		for(; n > 0; n--) {
			list.add(sc.nextInt()-x);
		}
		Collections.sort(list);
		int ab = -100;
		for(int i  = -99; i <= 99; i++) {
			if(!list.contains(i) && Math.abs(ab) > Math.abs(i)) {
				ab = i;
			}
		}
		System.out.println(x + ab);
		
	} FastScanner sc = new FastScanner(System.in); sc new FastScanner(System.in) int x = sc.nextInt() x sc.nextInt() sc.nextInt sc n = sc.nextInt(); n sc.nextInt() sc.nextInt sc ArrayList<Integer> list = new ArrayList<>(); list new ArrayList<>() for(; n > 0; n--) {
			list.add(sc.nextInt()-x);
		} ; n > 0 n 0 n-- n-- n {
			list.add(sc.nextInt()-x);
		} {
			list.add(sc.nextInt()-x);
		} list.add(sc.nextInt()-x) list.add list sc.nextInt()-x sc.nextInt() sc.nextInt sc x Collections.sort(list) Collections.sort Collections list int ab = -100; ab -100 100 for(int i  = -99; i <= 99; i++) {
			if(!list.contains(i) && Math.abs(ab) > Math.abs(i)) {
				ab = i;
			}
		} int i  = -99; int i  = -99; i -99 99 i <= 99 i 99 i++ i++ i {
			if(!list.contains(i) && Math.abs(ab) > Math.abs(i)) {
				ab = i;
			}
		} {
			if(!list.contains(i) && Math.abs(ab) > Math.abs(i)) {
				ab = i;
			}
		} if(!list.contains(i) && Math.abs(ab) > Math.abs(i)) {
				ab = i;
			} !list.contains(i) && Math.abs(ab) > Math.abs(i) !list.contains(i) list.contains(i) list.contains list i Math.abs(ab) > Math.abs(i) Math.abs(ab) Math.abs Math ab Math.abs(i) Math.abs Math i {
				ab = i;
			} ab = i ab i System.out.println(x + ab) System.out.println System.out System System.out x + ab x ab String[] args args static class FastScanner {
		private BufferedReader reader = null;
	    private StringTokenizer tokenizer = null;
	    public FastScanner(InputStream in) {
	        reader = new BufferedReader(new InputStreamReader(in));
	        tokenizer = null;
	    }

	    public String next() {
	        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    }

	    public String nextLine() {
	        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                return reader.readLine();
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }

	        return tokenizer.nextToken("\n");
	    }

	    public long nextLong() {
	        return Long.parseLong(next());
	    }

	    public int nextInt() {
	        return Integer.parseInt(next());
	    }

	    public double nextDouble() {
	         return Double.parseDouble(next());
	     }

	    public int[] nextIntArray(int n) {
	        int[] a = new int[n];
	        for (int i = 0; i < n; i++)
	            a[i] = nextInt();
	        return a;
	    }

	    public long[] nextLongArray(int n) {
	        long[] a = new long[n];
	        for (int i = 0; i < n; i++)
	            a[i] = nextLong();
	        return a;
	    }
	} FastScanner private BufferedReader reader = null; reader null private StringTokenizer tokenizer = null; tokenizer null public FastScanner(InputStream in) {
	        reader = new BufferedReader(new InputStreamReader(in));
	        tokenizer = null;
	    } FastScanner {
	        reader = new BufferedReader(new InputStreamReader(in));
	        tokenizer = null;
	    } reader = new BufferedReader(new InputStreamReader(in)) reader new BufferedReader(new InputStreamReader(in)) tokenizer = null tokenizer null InputStream in in public String next() {
	        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    } next {
	        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    } if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        } tokenizer == null || !tokenizer.hasMoreTokens() tokenizer == null tokenizer null !tokenizer.hasMoreTokens() tokenizer.hasMoreTokens() tokenizer.hasMoreTokens tokenizer {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        } try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            } IOException e {
	                throw new RuntimeException(e);
	            } throw new RuntimeException(e); new RuntimeException(e) {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } tokenizer = new StringTokenizer(reader.readLine()) tokenizer new StringTokenizer(reader.readLine()) return tokenizer.nextToken(); tokenizer.nextToken() tokenizer.nextToken tokenizer public String nextLine() {
	        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                return reader.readLine();
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }

	        return tokenizer.nextToken("\n");
	    } nextLine {
	        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                return reader.readLine();
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }

	        return tokenizer.nextToken("\n");
	    } if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                return reader.readLine();
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        } tokenizer == null || !tokenizer.hasMoreTokens() tokenizer == null tokenizer null !tokenizer.hasMoreTokens() tokenizer.hasMoreTokens() tokenizer.hasMoreTokens tokenizer {
	            try {
	                return reader.readLine();
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        } try {
	                return reader.readLine();
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            } IOException e {
	                throw new RuntimeException(e);
	            } throw new RuntimeException(e); new RuntimeException(e) {
	                return reader.readLine();
	            } return reader.readLine(); reader.readLine() reader.readLine reader return tokenizer.nextToken("\n"); tokenizer.nextToken("\n") tokenizer.nextToken tokenizer "\n" public long nextLong() {
	        return Long.parseLong(next());
	    } nextLong {
	        return Long.parseLong(next());
	    } return Long.parseLong(next()); Long.parseLong(next()) Long.parseLong Long next() next public int nextInt() {
	        return Integer.parseInt(next());
	    } nextInt {
	        return Integer.parseInt(next());
	    } return Integer.parseInt(next()); Integer.parseInt(next()) Integer.parseInt Integer next() next public double nextDouble() {
	         return Double.parseDouble(next());
	     } nextDouble {
	         return Double.parseDouble(next());
	     } return Double.parseDouble(next()); Double.parseDouble(next()) Double.parseDouble Double next() next public int[] nextIntArray(int n) {
	        int[] a = new int[n];
	        for (int i = 0; i < n; i++)
	            a[i] = nextInt();
	        return a;
	    } nextIntArray {
	        int[] a = new int[n];
	        for (int i = 0; i < n; i++)
	            a[i] = nextInt();
	        return a;
	    } int[] a = new int[n]; a new int[n] n for (int i = 0; i < n; i++)
	            a[i] = nextInt(); int i = 0; int i = 0; i 0 i < n i n i++ i++ i a[i] = nextInt(); a[i] = nextInt() a[i] a i nextInt() nextInt return a; a int n n public long[] nextLongArray(int n) {
	        long[] a = new long[n];
	        for (int i = 0; i < n; i++)
	            a[i] = nextLong();
	        return a;
	    } nextLongArray {
	        long[] a = new long[n];
	        for (int i = 0; i < n; i++)
	            a[i] = nextLong();
	        return a;
	    } long[] a = new long[n]; a new long[n] n for (int i = 0; i < n; i++)
	            a[i] = nextLong(); int i = 0; int i = 0; i 0 i < n i n i++ i++ i a[i] = nextLong(); a[i] = nextLong() a[i] a i nextLong() nextLong return a; a int n n public class Main {
	public static void main(String[] args) {
		FastScanner sc = new FastScanner(System.in);
		int x = sc.nextInt(), n = sc.nextInt();
		ArrayList<Integer> list = new ArrayList<>();
		for(; n > 0; n--) {
			list.add(sc.nextInt()-x);
		}
		Collections.sort(list);
		int ab = -100;
		for(int i  = -99; i <= 99; i++) {
			if(!list.contains(i) && Math.abs(ab) > Math.abs(i)) {
				ab = i;
			}
		}
		System.out.println(x + ab);
		
	}
	
	static class FastScanner {
		private BufferedReader reader = null;
	    private StringTokenizer tokenizer = null;
	    public FastScanner(InputStream in) {
	        reader = new BufferedReader(new InputStreamReader(in));
	        tokenizer = null;
	    }

	    public String next() {
	        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    }

	    public String nextLine() {
	        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                return reader.readLine();
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }

	        return tokenizer.nextToken("\n");
	    }

	    public long nextLong() {
	        return Long.parseLong(next());
	    }

	    public int nextInt() {
	        return Integer.parseInt(next());
	    }

	    public double nextDouble() {
	         return Double.parseDouble(next());
	     }

	    public int[] nextIntArray(int n) {
	        int[] a = new int[n];
	        for (int i = 0; i < n; i++)
	            a[i] = nextInt();
	        return a;
	    }

	    public long[] nextLongArray(int n) {
	        long[] a = new long[n];
	        for (int i = 0; i < n; i++)
	            a[i] = nextLong();
	        return a;
	    }
	}
} public class Main {
	public static void main(String[] args) {
		FastScanner sc = new FastScanner(System.in);
		int x = sc.nextInt(), n = sc.nextInt();
		ArrayList<Integer> list = new ArrayList<>();
		for(; n > 0; n--) {
			list.add(sc.nextInt()-x);
		}
		Collections.sort(list);
		int ab = -100;
		for(int i  = -99; i <= 99; i++) {
			if(!list.contains(i) && Math.abs(ab) > Math.abs(i)) {
				ab = i;
			}
		}
		System.out.println(x + ab);
		
	}
	
	static class FastScanner {
		private BufferedReader reader = null;
	    private StringTokenizer tokenizer = null;
	    public FastScanner(InputStream in) {
	        reader = new BufferedReader(new InputStreamReader(in));
	        tokenizer = null;
	    }

	    public String next() {
	        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    }

	    public String nextLine() {
	        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                return reader.readLine();
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }

	        return tokenizer.nextToken("\n");
	    }

	    public long nextLong() {
	        return Long.parseLong(next());
	    }

	    public int nextInt() {
	        return Integer.parseInt(next());
	    }

	    public double nextDouble() {
	         return Double.parseDouble(next());
	     }

	    public int[] nextIntArray(int n) {
	        int[] a = new int[n];
	        for (int i = 0; i < n; i++)
	            a[i] = nextInt();
	        return a;
	    }

	    public long[] nextLongArray(int n) {
	        long[] a = new long[n];
	        for (int i = 0; i < n; i++)
	            a[i] = nextLong();
	        return a;
	    }
	}
} Main
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.StringTokenizer;

public class Main {
	public static void main(String[] args) {
		FastScanner sc = new FastScanner(System.in);
		int x = sc.nextInt(), n = sc.nextInt();
		ArrayList<Integer> list = new ArrayList<>();
		for(; n > 0; n--) {
			list.add(sc.nextInt()-x);
		}
		Collections.sort(list);
		int ab = -100;
		for(int i  = -99; i <= 99; i++) {
			if(!list.contains(i) && Math.abs(ab) > Math.abs(i)) {
				ab = i;
			}
		}
		System.out.println(x + ab);
		
	}
	
	static class FastScanner {
		private BufferedReader reader = null;
	    private StringTokenizer tokenizer = null;
	    public FastScanner(InputStream in) {
	        reader = new BufferedReader(new InputStreamReader(in));
	        tokenizer = null;
	    }

	    public String next() {
	        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    }

	    public String nextLine() {
	        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                return reader.readLine();
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }

	        return tokenizer.nextToken("\n");
	    }

	    public long nextLong() {
	        return Long.parseLong(next());
	    }

	    public int nextInt() {
	        return Integer.parseInt(next());
	    }

	    public double nextDouble() {
	         return Double.parseDouble(next());
	     }

	    public int[] nextIntArray(int n) {
	        int[] a = new int[n];
	        for (int i = 0; i < n; i++)
	            a[i] = nextInt();
	        return a;
	    }

	    public long[] nextLongArray(int n) {
	        long[] a = new long[n];
	        for (int i = 0; i < n; i++)
	            a[i] = nextLong();
	        return a;
	    }
	}
}
