#include <fstream>
using namespace std;
ofstream fout("maxim5.out");
ifstream fin("maxim5.in");

int x, nr, Max, Max2, nr2 = 100000000;

int main()
{
    while(fin >> x) {
        nr++;
        if(!x) {
            if(nr <= nr2) {
                nr2 = nr; nr = 0;
                Max2 = max(Max2, Max); Max = 0;
            }
            else { nr = 0; Max = 0; }
        }
        else if(nr <= nr2 && x > Max) Max = x;
    }
    fout << Max2;
    return 0;
}