View Compilation Error

0_0_19866742_18650.cpp: In function 'int main(int, const char**)':
0_0_19866742_18650.cpp:29:29: error: expected primary-expression before 'int'
   memset(b, 0 ,sizeof((n+3)*int));
                             ^
0_0_19866742_18650.cpp:29:29: error: expected ')' before 'int'