#include <bits/stdc++.h>   const int N = 110;   using namespace std;   inline int read() {     int x = 0, f = 1;     int ch = getchar();     while (ch <  0  || ch >  9 ) {       if (ch ==  - ) {         f = -1;       }       ch = getchar();     }     while (ch <=  9  && ch >=  0 ) {       x = (x << 1) + (x << 3) + ch -  0 ;       ch = getchar();     }     return x * f;   }   int n, a[N];   int main() {     int q = read();     while (q--) {       bool flg = 0;       n = read();       for (int i = 1; i <= n; i++) {         a[i] = read();       }       sort(a + 1, a + 1 + n);       for (int i = 2; i <= n; i++) {         if (a[i] == a[i - 1] + 1) {           cout << 2 << endl;           flg = 1;           break;         }       }       if (!flg) cout << 1 << endl;     }     return 0;   }   