hihocoder 1584 Bounce

hihocoder 1584 Bounce

here

#include<bits/stdc++.h>
using namespace std;
long long gcd(long long a, long long b){
    return b == 0 ? a : gcd(b,a%b);
}
long long lcm(long long a, long long b){
    return a*b/gcd(a,b);
}
int main(){
    long long n , m;
    while(~scanf("%lld %lld", &n, &m)){
        long long l = lcm(n-1,m-1);
        long long a = l/(m-1) , b = l/(n-1);
        printf("%lld
",l - a*b + a + b);
    }
    return 0;
}