pair<int, pair<int, int> > res;
int a[200020], b[200020];
int n, m, x, y, d, cur;

int main()
{
	#ifndef ONLINE_JUDGE
		freopen("input.txt","rt",stdin);
		freopen("output.txt","wt",stdout);
	#endif
		cin>>n;
		for (int i=0; i<n; i++) scanf("%d", a+i);
		cin>>m;
		for (int i=0; i<m; i++) scanf("%d", b+i);
		sort(a, a+n);
		sort(b, b+m);
		for (int i=0; i<n; i++) {
			d=a[i]-1;
			x=(n-i)*3+i*2;
			y=lower_bound(b, b+m, d)-b;
			if (b[y]==d) y++;
			y=(m-y)*3+y*2;
			cur=x-y;
			res=max(res, mp(cur, mp(x, y)));
		}
		cout<<res.S.F<<":"<<res.S.S;
    return 0;
}