#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <cmath>
#include <cstring>
#include <iostream>
#include <iomanip>
#include <vector>
#include <list>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <string>
#include <utility>
#include <sstream>
#include <algorithm>
#include <ctime>
#include <cassert>
#include <limits>
using  namespace  std;

#define PI acos(-1.0)
#define mem(a,b) memset(a,b,sizeof(a))
#define gcd(a,b) __gcd(a,b)
#define pb push_back
#define mp make_pair
#define x first
#define y second
#define Sort(x) sort(x.begin(),x.end())
#define FOR(i, b, e) for(int i = b; i <= e; i++)
#define FORR(i, b, e) for(int i = b; i >= e; i--)
#define FORI(i, s) for (__typeof ((s).end ()) i = (s).begin (); i != (s).end (); ++i)
#define pr(x) cout<<x<<"\n"
#define pr2(x,y) cout<<x<<" "<<y<<"\n"
#define pr3(x,y,z) cout<<x<<" "<<y<<" "<<z<<"\n";
#define ppr(a) cout<<a.x<<" "<<a.y<<"\n"
#define READ(f) freopen(f, "r", stdin)
#define WRITE(f) freopen(f, "w", stdout)

typedef  long long ll;
typedef  pair <int, int> pii;
typedef  pair <double , double> pdd;
typedef  pair <ll , ll > pll;
typedef  vector <int> vi;
typedef  vector <pii> vpii;
typedef  vector <ll > vl;

//int dx[]={1,0,-1,0};int dy[]={0,1,0,-1}; //4 Direction
//int dx[]={1,1,0,-1,-1,-1,0,1};
//int dy[]={0,1,1,1,0,-1,-1,-1};//8 direction
//int dx[]={2,1,-1,-2,-2,-1,1,2};
//int dy[]={1,2,2,1,-1,-2,-2,-1};//Knight Direction

#define MAX 100007
#define EPS 1e-9

bool v[505][505][505];
struct BearPlaysDiv2{

string equalPiles(int A, int B, int C)
{
    string ret="possible";
    mem(v,false);
    if((A+B+C)%3==0&&posi(A,B,C)) ret="possible";
    else ret="impossible";
    return ret;
}
bool posi(int a,int b,int c)
{

    vi ar;
    ar.pb(a);
    ar.pb(b);
    ar.pb(c);
    Sort(ar);

     if(ar[0]==ar[1]&&ar[1]==ar[2])return 1;

    if(v[ar[0] ][ar[1] ][ar[2] ])return 0;
    //if(ar[0]==3&&ar[1]==498)pr3(a,b,c);
    v[ar[0] ][ar[1] ][ar[2] ]=true;
    int ans=0;
    if(ar[0]!=ar[1])
    {
       // if(ar[0]==480&&ar[1]==483)pr3(a,b,c);
        ans+=posi(2*ar[0],ar[1]-ar[0],ar[2]);
    }

    if(ar[0]!=ar[2])
    ans+=posi(2*ar[0],ar[1],ar[2]-ar[0]);
    if(ar[1]!=ar[2])
    ans+=posi(ar[0],2*ar[1],ar[2]-ar[1]);
    return (ans!=0);
}

};