UVA-10127 Ones （数论）

# include<iostream>
# include<cstdio>
# include<cstring>
# include<algorithm>
using namespace std;
int solve(int n)
{
    int cnt=0;
    unsigned long long x=0;
    while(1){
        x=(x%n)*(10%n)+1;
        x%=n;
        ++cnt;
        if(x==0)
            return cnt;
    }
}
int main()
{
    int n;
    while(scanf("%d",&n)!=EOF)
    {
        printf("%d\n",solve(n));
    }
    return 0;
}