View Compilation Error

0_0_36697111_751.cpp: In function 'int main()':
0_0_36697111_751.cpp:60:12: error: 'q' was not declared in this scope
   for(ri i=q[0];i>=1;--i)q[i]=0;q[0]=0;
            ^
0_0_36697111_751.cpp:60:33: error: 'q' was not declared in this scope
   for(ri i=q[0];i>=1;--i)q[i]=0;q[0]=0;
                                 ^