View Compilation Error

0_0_25843159_11599.cpp: In function 'int main()':
0_0_25843159_11599.cpp:38:13: error: 'ans' was not declared in this scope
         mst(ans,0);
             ^
0_0_25843159_11599.cpp:6:25: note: in definition of macro 'mst'
 #define mst(a,b) memset(a,b,sizeof(a))
                         ^