1 #include<iostream>
2 #include<string>
3 #include<queue>
4 #include<stack>
5 #include<vector>
6 #include<map>
7 #include<cstdio>
8 #include<cstdlib>
9 #include<algorithm>
10 #include<set>
11 #include<list>
12 #include<iomanip>
13 #include<cstring>
14 #include<cmath>
15 #include<limits>
16 using namespace std;
17
18 #define au auto
19 #define debug(i) cout<<"<debug> "<<i<<"<\debug>"<<endl
20 #define mfor(i,a,b) for(register int i=(a);i<=(b);i++)
21 #define mrep(i,a,b) for(register int i=(a);i>=(b);i--)
22 #define LLL __int128
23 #define Re register
24 #define il inline
25 #define mem(a,b) memset(a,(b),sizeof(a))
26 typedef pair<int, int> intpair;
27 typedef long long int LL;
28 const int INF = 0x3f3f3f3f;
29 const long long int INFLL = 0x3f3f3f3f3f3f3f3f;
30
31 int T;
32 int n;
33 int st[1010];
34
35 int main()
36 {
37 cin >> T;
38 mfor(i, 1, T)
39 {
40 int n;
41 cin >> n;
42 mfor(i, 1, n) cin >> st[i];
43 sort(st + 1, st + 1 + n);
44 bool f = true;
45 mfor(i, 2, n)
46 {
47 if (st[i - 1] + 1 == st[i])
48 {
49 cout << 2 << endl;
50 f = false;
51 break;
52 }
53 }
54 if(f) cout << 1 << endl;
55 }
56 }