View Compilation Error

0_0_32676723_13592.cpp: In function 'int main()':
0_0_32676723_13592.cpp:26:53: error: 'pop' was not declared in this scope
                     p[cnt++]=atan2(po[j].y-po[i].y, pop[j].x-po[i],x);
                                                     ^
0_0_32676723_13592.cpp:26:68: error: 'x' was not declared in this scope
                     p[cnt++]=atan2(po[j].y-po[i].y, pop[j].x-po[i],x);
                                                                    ^