#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;
}