#include <cmath>
#include <cstdio>
#include <cstring>

#include <vector>
#include <algorithm>

using namespace std;
typedef long double ld;
typedef long long llint;

const ld eps = 1e-9;
const int deg = (1 << 17)+1;
const int shift = 10001;

struct comp {
   ld x, y;
   comp() { x = y = 0.0; }
   comp( ld X, ld Y ) { x = X; y = Y; }
   comp( ld phi ) { x = cos( phi ); y = sin( phi ); }
};

int N;
comp p[ deg ]; int q[ deg ], r[ deg ];
comp s[ deg ], c[ deg ];
comp tmp[ deg ];

inline comp operator+( comp a, comp b ) { return comp( a.x+b.x, a.y+b.y ); }
inline comp operator-( comp a, comp b ) { return comp( a.x-b.x, a.y-b.y ); }
inline comp operator*( comp a, comp b ) { return comp( a.x*b.x-a.y*b.y, a.x*b.y+a.y*b.x ); }

void fft( comp *a, int x, int n, int t ) {
   if( n == 1 ) return;

   int h = ( n >> 1 );
   comp w( 1.0, 0.0 ), cw;
   comp W( t*2.0*M_PI/n );

   for( int i = 0; i < n; ++i ) tmp[i] = a[x+i];
   for( int i = 0; i < n; i += 2 ) a[x+(i>>1)] = tmp[i];
   for( int i = 1; i < n; i += 2 ) a[x+h+(i>>1)] = tmp[i];

   fft( a, x, h, t );
   fft( a, x+h, h, t );

   for( int i = 0; i < n; ++i ) tmp[i] = a[x+i];
   for( int i = 0; i < h; ++i ) {
      cw = w*tmp[i+h];
      a[x+i] = tmp[i] + cw;
      a[x+h+i] = tmp[i] - cw;
      w = w*W;
   }
}

inline void conv( comp *a, comp *b, int n ) {
   for( int i = 0; i < n; ++i ) c[i] = b[i];

   fft( a, 0, n, +1 );
   fft( c, 0, n, +1 );

   for( int i = 0; i < n; ++i )
      a[i] = a[i]*c[i];

   fft( a, 0, n, -1 );

   for( int i = 0; i < n; ++i ) {
      a[i].y = 0.0;
      a[i].x = round( a[i].x/n+0.2 );
   }
}

inline void solve( comp *p, int *q, int *r, int n ) {
   for( int i = 0; i < n; ++i ) s[i] = p[i];

   conv( s, p, n );

   for( int i = 0; i < n; ++i )
      s[i].x -= 3*q[i];

   conv( s, p, n );

   for( int i = 0; i < n; ++i )
      s[i].x += 2*r[i];
}

int main( void )
{
   scanf( "%d", &N );

   for( int i = 0; i < N; ++i ) {
      int a; scanf( "%d", &a );
      p[a+shift] = comp( 1.0, 0.0 );
      q[2*a+2*shift] = 1;
      r[3*a+3*shift] = 1;
   }

   solve( p, q, r, 1 << 16 );

   for( int i = 0; i < deg; ++i ) {
      if( fabs( s[i].x ) < eps ) continue;
      printf( "%d : %lld\n", i-3*shift, (llint)( s[i].x+0.1 )/6 );
   }

   return 0;
}