Just a Numble

Description
Now give you two integers n m, you just tell me the m-th number after radix point in 1/n,for example n=4,the first numble after point is 2,the second is 5,and all 0 followed

Input
Each line of input will contain a pair of integers for n and m(1<=n<=10^7,1<=m<=10^5)

Output
For each line of input, your program should print a numble on a line,according to the above rules

Sample Input
4 2
5 7
123 123

Sample Output
5
0

8

我只想说平时不切题，赛时徒伤悲！！！

可以说这是一个公式，注意n=1的情况。

#include<stdio.h>
int main()
{
    int n,m,i;
    while(scanf("%d%d",&n,&m)!=EOF)
    {
        int ans,a=10,k;
        if(n==1)
        printf("0\n");
        for(i=0;i<m;i++)
        {
            ans=a/n;
            k=a%n;
            a=k*10;
        }
        printf("%d\n",ans);
    }
    return 0;
}