杭电ACM 1409Climbing Worm----20140801

#include<stdio.h>
int main()
{
    int n,u,d,s,s1;
    while(scanf("%d%d%d",&n,&u,&d)!=EOF&&!(n==0&&u==0&&d==0))
    {
         s=0;s1=0;
         while(1)
         {
             s+=u;
             s1++;
             if(s>=n) break;           
             s-=d;
             s1++;   
         }
         printf("%d\n",s1);
    }
    return 0;
}