#include<stdio.h> int n;int element[25][4];int state[25];int result[25]; int q; void initial(){ int i,j; for(i=0;i<25;i++) { for(j=0;j<4;j++) { element[i][j]=0; } state[i]=0; result[i]=0; } q=0;} int backtrack(int ipos){ int i; if(ipos==n*n) { return 1; } else { for(i=0;i<q;i++) { if(state[i]==0) { continue; } else { if(ipos>=n) { if(element[result[ipos-n]][2]!=element[i][0]) { continue; } } if(ipos%n!=0) {if(element[result[ipos-1]][1]!=element[i][3]){ continue;} } state[i]--; result[ipos]=i; if(backtrack(ipos+1)==1) return 1; state[i]++; }} } return 0;}int main(){ int i,j,index; index=0; int top,right,bottom,left; scanf("%d",&n); while(n) { initial(); index++; for(i=0;i<n*n;i++) { scanf("%d %d %d %d",&top,&right,&bottom,&left); for(j=0;j<q;j++) { if(element[j][0]==top&&element[j][1]==right&&element[j][2]==bottom&&element[j][3]==left) { state[j]++; break; } } if(j==q) { element[q][0]=top; element[q][1]=right; element[q][2]=bottom; element[q][3]=left; state[q]=1; q++; } } if(index>1) { printf("n");}printf("Game %d: ",index); if(backtrack(0)) { printf("Possiblen");} else { printf("Impossiblen");} scanf("%d",&n); } return 0; }
