#include <complex>
#include <cstdio>

int q[2001],r[2001];
int root(int a){return q[a]?q[a]=root(q[a]):a;}
bool merge(int a,int b){a=root(a),b=root(b); return a^b?r[a]<r[b]?q[a]=b,++r[b]:q[b]=a,++r[a]:0;}

std::complex<long long> sp[2000], tp[1000];
template <class T> long long operator^(T a,T b){return (a*conj(b)).imag();}

bool collide(int a,int b){
  return sp[a]!=sp[b]
    and ((sp[b]-sp[a])^(tp[a]-sp[a]))*(__int128)((tp[b]-sp[a])^(tp[a]-sp[a]))<=0
    and ((sp[a]-sp[b])^(tp[b]-sp[b]))*(__int128)((tp[a]-sp[b])^(tp[b]-sp[b]))<=0;
}

int main(){
  int w,p; scanf("%d%d",&w,&p);
  for (int i=0,a,b; i<w; i++) scanf("%d%d",&a,&b), sp[i+p]={a,b};
  for (int i=p,a,b,c; i--;) scanf("%d%d%d",&a,&b,&c), sp[i]=sp[--a+p], tp[i]={b,c};

  for (int i=p; i--;)
    for (int j=p; j--;)
      if (collide(i,j) and merge(i*2+1,j*2+2), root(i*2+1)==root(i*2+2))
        return !puts("impossible");
  return !puts("possible");
}