#include<iostream>
#include<string>
using namespace std;
/*
TASK:money
LANG:C++
*/
int main()
{
 int n=1,i,n1=0,nm=0,i2;
 string s,m="a",t;
 s[0]=0;
 while(s[n-1]!='#')
 {
  cin>>s;
  n=s.size();
  for(i=0;i<n;i++)
  {
   if(s[i]>='0'&&s[i]<='9')t[n1++]=s[i];
   if((s[i]<'0'||s[i]>'9')&&n1)
   {
    if(n1>nm){nm=n1;m=t;}
    else
     if(n1==nm)
      for(i2=0;i2<n1;i2++)if(t[i2]>m[i2]){nm=n1;m=t;}
    n1=0;
   }
  }
 }
 if(m=="a")cout<<"NO"<<endl;
 else cout<<m<<endl;
 return 0;
}
