#include <iostream>
typedef long long ll;
using namespace std;
bool ll_is_valid(ll t, ll N, ll x, ll y)
{
return t / x + (t - x) / y >= N;
}
ll f(ll N, ll x, ll y)
ll R = 1;
while (!ll_is_valid(R,N,x,y)) R *= 2;
ll L = R / 2;
while(R - L > 1)
ll M = (L + R) / 2;
if (!ll_is_valid(M,N,x,y)) {L = M;}
else {R = M;}
return R;
int main()
ll N,x,y;
cin >> N >> x >> y;
if(x > y) swap( x, y );
cout << f(N, x, y) << std::endl;
#include <iostream>
typedef long long ll;
using namespace std;
bool ll_is_valid(ll t, ll N, ll x, ll y)
{
return t / x + (t - x) / y >= N;
}
ll f(ll N, ll x, ll y)
{
ll R = 1;
while (!ll_is_valid(R,N,x,y)) R *= 2;
ll L = R / 2;
while(R - L > 1)
{
ll M = (L + R) / 2;
if (!ll_is_valid(M,N,x,y)) {L = M;}
else {R = M;}
}
return R;
}
int main()
{
ll N,x,y;
cin >> N >> x >> y;
if(x > y) swap( x, y );
cout << f(N, x, y) << std::endl;
}
{
if (tnum < tden)
{
temp = tnum;
tnum = tden;
tden = temp;
}
tnum = tnum - tden;
}
gcd = tden; //вычисляем наибольший общий делитель
numerator = numerator / gcd; //делим числитель и знаменатель на
НОД, получаем сокращенную дробь
denominator = denominator / gcd;