新手小程序求助

#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[])
{
  int kkk,a,b,sum,average,u;
  average=0;
  b=0;
  printf(“How many grades will you be entering:\n”);
  scanf(“%i”,&kkk);
  for(i=0;i<=kkk;++i);
  {printf(“Enter grade #%i:”,i);
  scanf(“%i\n”,&sum);
  average+=sum;
  u=average/a;
  if(sum<=59)
  b++;
}
printf(“grade average=%i\n”,u);
printf(“Numberof failures=%i”,b);

 
 
 
  system(“PAUSE”); 
  return 0;
}
我输入kkk任何数值的时候 I的数值不知道为什么会变成K+1 奇怪啊 请各位大大指点一下谢谢了