#include<iostream> #include<cstdio> #include<cstring> #include<string> #include<vector> #include<cmath> #include<algorithm> #include<map> #include<queue> #include<deque> #include<iomanip> #include<tuple> using namespace std; typedef long long int LL; typedef pair<int,int> P; typedef pair<LL,int> LP; const int INF=1<<30; const LL MAX=1e9+7; void array_show(int *array,int array_n,char middle=' '){ for(int i=0;i<array_n;i++)printf("%d%c",array[i],(i!=array_n-1?middle:'\n')); } void array_show(LL *array,int array_n,char middle=' '){ for(int i=0;i<array_n;i++)printf("%lld%c",array[i],(i!=array_n-1?middle:'\n')); } LL gcd(LL a,LL b){ if(a<b)return gcd(b,a); if(b==0)return a; return gcd(b,a%b); } int main(){ int n,m; int i,j,k; LL a,b,c,d; LL s=1; cin>>a>>b>>c; a--; d=gcd(b,c); s+=a/b+a/c; if(a/b>=c/d){ c/=d; c*=b; s-=a/c; } cout<<s<<endl; }