#import<bits/stdc++.h>

main(){
	int n=9,x=0,m;
	int a[10];
	for(;n--;)scanf("%d",a+n);
	n=10;
	for(;--n;){
		m=9;
		//printf("%d\n",n);
		for(;m--;){
			x+=a[m]==n?1:0;
			//printf("%d %d\n",a[m],x);
		}
		if(x>=3){
			printf("%d\n",n);
			return 0;
		}
	}
}