供参考,49 :
#include<stdio.h>
#include<stdlib.h>
int main()
{
int a,b,x,y,i,count=0;
for(i=4;i<=100;i+=2)
{
for(a=2;a<=i/2;a++)
{
x=0;
for(b=2;b < a;b++)
{
if(a%b==0)
{
x++;
break;
}
}
if(x >= 1) continue;
y=0;
for(b=2;b < (i-a);b++)
{
if((i-a)%b==0)
{
y++;
break;
}
}
if(x==0 && y==0)
{
count++;
break;
}
}
}
printf("%d\n",count);
return 0;
}