hdu 相遇周期

 #include <cstdio>
 #include <cstring>
 #include <algorithm>
 using namespace std;

 int main()
 {
     int t,a,b,c,d;
     scanf("%d",&t);
     while(t--)
     {
         scanf("%d/%d %d/%d",&a,&b,&c,&d);
         int m=__gcd(a,b);
         a/=m;b/=m;
         int x=__gcd(c,d);
         c/=x;d/=x;
         if(__gcd(b,d)==)
         {
             printf("%d\n",a/(__gcd(a,c))*c);
         }
         else
             printf("%d/%d\n",a/(__gcd(a,c))*c,__gcd(b,d));
     }
     return ;
 }