#include <bits/stdc++.h>
#define fi first
#define se second
#define vi_a vector<int>a;
#define p_b push_back
#define ll long long
#define pll pair<ll,ll>
#define pii pair<int,int>
#define m_p make_pair
#define fast_io cin.tie(0);cout.tie(0);ios_base::sync_with_stdio(0);
#define getfiles ifstream cin("input.txt");ofstream cout("output.txt");
#define closefiles cin.close();cout.close();
#define all(x) x.begin(),x.end()
#define sset ordered_set
#define sqr(x) (x)*(x)
#define pw(x) (1ll << x)
#define sz(x) (int)x.size()
#define endl "\n"
struct tree{
    ll val;
    tree* left=NULL;
    tree* right=NULL;
    tree(ll a,tree* l,tree* r){
        val=a;
        left=l;
        right=r;
    }
};
ll add(tree* beg, ll x){
    tree* psh=new tree(x,NULL,NULL);
    tree* cur=beg;
    while(cur){
         if(cur->val>x){
            if(cur->left){cur=cur->left;}
            else{
                cur->left=psh;
                return 1;
            }
        }
        else if(cur->val<x){
            if(cur->right){cur=cur->right;}
            else{
                cur->right=psh;
                return 1;
            }
        }
        else{
            return 2;
        }
    }
    return 1;
}
ll maxx(tree* beg){
    tree* cur=beg->left;
    ll dd=cur->val;
    while(cur->right!=NULL){
        cur=cur->right;
        if(cur->right==NULL){
            return dd;
        }
        dd=cur->val;
    }
    return dd;
}
bool cmp(ll a,ll b){
    return a>b;
}
using namespace std;

int main()
{

    tree* beg=new tree(INT_MAX,NULL,NULL);
    ll  k=-1;
    while(true){
        string a;

        cin>>k;
        if(k==0){
            break;
        }
        ll ok=add(beg,k);
    }
    ll ans=maxx(beg);
    cout<<ans;

    return 0;
}