输入两个数，求这两个数之间所有素数的和？
下面是我的代码。错误很多，但我不知道怎么改
# include <stdio.h>
# include <math.h>
int main()
{
    int m,n,x,t,r,s=0;
    scanf("%d%d",&m,&n);
    while(m<=n)
    {
        x=m;
        while(t<=sqrt(m))
        {
            r=m%t;
            if(r!=0)t=t+1;
            else
            {
                x=0;
                break;
            }
        }
        s=s+x;
        m=m+1;
    }
    printf("%d\n",s);
    return 0;
}