View Compilation Error

0_0_17693888_13609.cpp:27:4: error: 'MAXN' was not declared in this scope
 }P[MAXN], Q[MAXN];
    ^
0_0_17693888_13609.cpp:27:13: error: 'MAXN' was not declared in this scope
 }P[MAXN], Q[MAXN];
             ^
0_0_17693888_13609.cpp: In function 'int main()':
0_0_17693888_13609.cpp:50:18: error: 'P' was not declared in this scope
             cin>>P[i].x>>P[i].y;
                  ^
0_0_17693888_13609.cpp:51:14: error: 'P' was not declared in this scope
         sort(P,P+n);
              ^
0_0_17693888_13609.cpp:62:21: error: 'Q' was not declared in this scope
                     Q[m++]=P[j]-P[i];
                     ^
0_0_17693888_13609.cpp:66:35: error: 'Q' was not declared in this scope
                 int gcd=__gcd(abs(Q[j].x),abs(Q[j].y));
                                   ^
0_0_17693888_13609.cpp:73:18: error: 'Q' was not declared in this scope
             sort(Q,Q+m);
                  ^