import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String s = sc.nextLine();
        StringBuilder sb = new StringBuilder(s);
        sb.deleteCharAt(sb.length() - 1);//删掉末尾的方括号
        sb.deleteCharAt(0);//删掉开头的方括号
        String[] v1 = String.valueOf(sb).split(",");
        int[] v2 = new int[v1.length];
        for(int i = 0; i < v1.length; ++i) v2[i] = Integer.valueOf(v1[i]);
        Map<Integer, Integer> m = new HashMap<>();//用map来计数各整数的个数
        for(int i = 0; i < v2.length; ++i){
            if(m.containsKey(v2[i])){
                int temp = m.get(v2[i]);
                m.put(v2[i], temp + 1);
                if(m.get(v2[i]) >= v2.length/2){//找到众数之后就直接返回
                    System.out.println(v2[i]);
                    return;
                }
            }else m.put(v2[i], 1);
        }
        if(v2.length == 1) System.out.println(v2[0]);//数组中仅1个元素,直接返回
    }
}