int main()
{
	char l[1000];
	int i,num[1000],j,rate,k,circle,a;
	scanf("%s",&l);
	i=0;
	rate=1;
	int terminalnum[1000]={0};
	while(l[i]!='\0')
	{
		for(j=1;l[i]!=','&&l[i]!='\0';i++,j++)
		{
			num[j]=l[i]-'0';
		}
		for(k=0;k<j-1;k++)
		{
			a=1;
			for(circle=1;circle<=k;circle++)
			{
				a*=10;
			}
			terminalnum[rate]+=a*num[j-k-1];
		}
		if(l[i]=='\0')
		{
			break;
		}else{
			i+=1;
		}
		rate+=1;
	}
	int max,m,n,min;
	n=0;
	max=0;
	for(m=1;m<=rate;m++)
	{
		if(terminalnum[m]<max)
		{
			max=max;
		}else{
			if(terminalnum[m]>max)
			{
				max=terminalnum[m];
			}else{
				n+=1;
			}
		}
	}
	if(n==rate-1)
	{
		printf("No\n");
	}else{
		for(m=1;m<=rate;m++)
		{
			if(terminalnum[m]==max)
			{
				terminalnum[m]=-1;
			}
		}
		min=0;
		for(m=1;m<=rate;m++)
		{
		    if(terminalnum[m]<min)
			{
			     min=min;
			}else{
				 min=terminalnum[m];
			}
		}
	printf("%d\n",min);
	}
	return 0;
}