View Compilation Error

0_0_22002837_24636.cpp: In function 'void shai()':
0_0_22002837_24636.cpp:27:37: error: 'memset' was not declared in this scope
 #define Ms(a,b) memset(a,b,sizeof(a))
                                     ^
0_0_22002837_24636.cpp:41:2: note: in expansion of macro 'Ms'
  Ms(isprime, 1);
  ^