#include <iostream>
#include <cmath>
#include <string>
#include <vector>
#include <algorithm>
#include <iomanip>
#include <map>
#include <unordered_set>
using namespace std;
long long UCLN(long long a, long long b){
    if(b==0){
        return a;
    } else {
        return UCLN(b,a%b);
    }
}
long long BCNN(long long a, long long b){
    return (a*b/UCLN(a,b) );
}
class PhanSo{
private:
    long long tuso, mauso;
public:
    PhanSo(){
        tuso = 1;
        mauso = 1;
    }
    PhanSo(int n, int d){
        tuso = n;
        mauso = d;
    }
    friend istream& operator>>(istream& in, PhanSo& f) {
        cin >> f.tuso >> f.mauso;
        return in;
    }
    void rutgon(){
        long long ts = tuso, ms = mauso;
        tuso = tuso/UCLN(ts, ms);
        mauso = mauso/UCLN(ts,ms);
    }
    friend PhanSo operator+(PhanSo &p, PhanSo &q){
        PhanSo ketqua;
        long long msc = BCNN(p.mauso,q.mauso);
        ketqua.mauso = msc;
        ketqua.tuso = msc/p.mauso*p.tuso + msc/q.mauso*q.tuso;
        ketqua.rutgon();
        return ketqua;
    }
    friend ostream& operator<<(ostream& out, PhanSo&f) {
        cout << f.tuso << "/" << f.mauso;
        return out;
    }


};

int main() {
    PhanSo p(1,1), q(1,1);
    cin >> p >> q;
    cout << p + q;
    return 0;
}