/* written by Pankaj Kumar. country:-INDIA */ #include using namespace std; typedef long long ll ; typedef set> spi; typedef set> spl; typedef vector> vpi; typedef vector vi; typedef vector vl; typedef vector vb; typedef vector vc; typedef vector> vpl; typedef vector vs; typedef map ml; typedef set ss; typedef setsc; typedef set si; typedef set sl; #define pan cin.tie(0);cout.tie(0);ios_base::sync_with_stdio(0); // define values. #define mod 1000000007 #define phi 1.618 /* Bit-Stuff */ #define get_set_bits(a) (__builtin_popcount(a)) #define get_set_bitsll(a) ( __builtin_popcountll(a)) #define get_trail_zero(a) (__builtin_ctz(a)) #define get_lead_zero(a) (__builtin_clz(a)) #define get_parity(a) (__builtin_parity(a)) /* Abbrevations */ #define ff first #define ss second #define mp make_pair #define line cout<>arr[i]; // Some print #define no cout<<"NO"<>test;while(test--) // sort #define all(V) (V).begin(),(V).end() #define srt(V) sort(all(V)) #define srtGreat(V) sort(all(V),greater()) // function ll power(ll x,ll y) { ll res=1; while(y>0) { if(y%2==1)res*=x; y/=2; x*=x; } return res; } /* ascii value A=65,Z=90,a=97,z=122 */ /* -----------------------------------------------------------------------------------*/ ll solve() { ll n; cin>>n; set s; ll temp; for(ll i=0;i>temp; s.insert(temp); } n=s.size(); cout<<(n*(n-1))/2<