HDU_1495_模拟

#include<iostream>
#include<cstdio>
using namespace std;

int gcd(int a,int b)
{
    return b?gcd(b,a%b):a;
}
int main()
{
    int s,m,n;
    while(cin >> s >> n >> m && s && n && m)
    {
        int g = gcd(m,n);
        int a = s/g;
        if(a%2)
        {
            printf("NO\n");
            continue;
        }
        int big = max(m,n)/g;
        int small = min(m,n)/g;
        int x = a-big,y = big,z = 0,num = 1;;
        while(y != a/2)
        {
            if(y > small)
            {
                y -= small;
                x += small;
                num += 2;
            }
            else if(y < small)
            {
                z = y;
                x -= big;
                y = big;
                y -= small-z;
                x += small;
                z = 0;
                num += 4;
            }
            else
            {
                num = 0;
                break;
            }
        }
        if(!num)    printf("NO");
        else
        {
            if(z)   printf("%d\n",num+1);
            else    printf("%d\n",num);
        }
    }
    return 0;
}