А можете бабочку в программе кумир чертежник

#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;

}

//PascalABC.NET 3.1 сборка 1219
procedure PrintMatrix(a: array[,] of integer);
begin
    for var i := a.GetLowerBound(0) to a.GetUpperBound(0) do
    begin
        writeln;
        for var j := a.GetLowerBound(1) to a.GetUpperBound(1) do
            write(a[i, j], ' ');
    end;
    writeln;
end;

begin
    var a := MatrixRandom(9, 9, 10, 99);
    PrintMatrix(a);
    var i := (a.GetLowerBound(0) + a.GetUpperBound(0)) div 2 + (a.GetLowerBound(0) + a.GetUpperBound(0)) mod 2;
    var j := (a.GetLowerBound(1) + a.GetUpperBound(1)) div 2 + (a.GetLowerBound(1) + a.GetUpperBound(1)) mod 2;
    writeln('A[', i, ', ', j, '] = ', a[i, j]);
end.