ex128

#include<iostream>
using namespace std;

int cmmdc(int a,int b)
  {
   int p,r;
   p=a*b;

   while(a%b!=0)
    {
     r=a%b;
     a=b;
     b=r;
    }
   return p/b;
 }

 int main()
  {
   int n,a,b;
   cin>>n>>a>>b;
   cout<<n/a-n/cmmdc(a,b);
  }