#include<bits/stdc++.h>
using namespace std;
using i64 = int_fast64_t;
#define rep(i, N) for(int (i) = 0; (i) < (N); (i)++)
#define all(v) (v).begin(), (v).end()
#define eb emplace_back

int main(){
    int A,B;
    cin >> A >> B;
    int L = lcm(A, B);
    cout << L - L/A - L/B + L/(A+B) << endl;
}