题目内容：

C+++如何完善填空?计算1到M(M为偶数)之间奇数及偶数的和.
#include
#define M 100
void main()
{ int a,b,i;
a=0;b=0;
//
___(2)___;
}
printf("sum of evens is %d\n",b);
printf("sum of odds is %d\n",a);
}
中间是i