#include <bits/stdc++.h>

 using namespace std;

 const int maxn = ;

 const int maxm = maxn * maxn;

 typedef struct R {

   int x, y, z;

   R(){}

   R(int x, int y, int z) : x(x), y(y), z(z) {}

   bool operator == (R t) {

     return x == t.x && y == t.y && z == t.z;

   }

 }R;

 typedef struct S {

   int i, j;

   int s;

 }S;

 vector<R> ret;

 int n, m;

 int a[maxn];

 S s[maxm];

 bool cmp(R a, R b) {

   if(a.x == b.x) {

     if(a.y == b.y) return a.z < b.z;

     return a.y < b.y;

   }

   return a.x < b.x;

 }

 int main() {

   // freopen("in", "r", stdin);

   while(~scanf("%d", &n)) {

     m = ; ret.clear();

     for(int i = ; i < n; i++) {

       scanf("%d", &a[i]);

     }

     sort(a, a+n);

     for(int i = ; i < n; i++) {

       for(int j = i+; j < n; j++) {

         s[m].i = i; s[m].j = j; s[m].s = a[i] + a[j];

         m++;

       }

     }

     for(int i = ; i < m; i++) {

       int x = -s[i].s;

       int id = lower_bound(a, a+n, x) - a;

       if(a[id] == x && id != s[i].i && id != s[i].j) {

         int x = a[s[i].i], y = a[s[i].j], z = a[id];

         if(x > y) swap(x, y);

         if(x > z) swap(x, z);

         if(y > z) swap(y, z);

         ret.push_back(R(x,y,z));

       }

     }

     if(ret.size() == ) {

       puts("No Solution");

       continue;

     }

     sort(ret.begin(), ret.end(), cmp);

     ret.erase(unique(ret.begin(), ret.end()), ret.end());

     for(int i = ; i < ret.size(); i++) {

       printf("%d %d %d\n", ret[i].x, ret[i].y, ret[i].z);

     }

   }

   return ;

 }