include <bits/stdc++.h>

using namespace std;

typedef long long ll; typedef long double ld;

void solve() {

long long a;
vector<long long>v,v1;
set<long long>s;
while(cin>>a){
    if(a == 0) break;
    v.push_back(a);
}
for(int i=0;i<v.size();i++){
    s.insert(v[i]);
}
for(auto i = s.begin();i!=s.end();i++){
    v1.push_back(*i);
}
cout<<v1[v1.size()-2]<<endl;

}

int main() {

ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL);
solve();
return 0;

}