#include <bits/stdc++.h>   using namespace std;   const unsigned long long N = 1e10;   int getLen(unsigned long long a) {     int len = 0;     while (a) {       len++;       a /= 10;     }     return len;   }   unsigned long long gcd(unsigned long long a, unsigned long long b) {     return b == 0 ? a : gcd(b, (a % b));   }   unsigned long long lcm(unsigned long long a, unsigned long long b) {     unsigned long long t = gcd(a, b);     if (getLen(a / t) + getLen(b) > 22) return 0;     return a / gcd(a, b) * b;   }   int main() {     unsigned long long t, w, b;     unsigned long long p;     cin >> t >> w >> b;     if (w == b) {       printf( 1/1 n );       return 0;     }     unsigned long long mi = min(w, b);     if (t < mi) {       printf( 1/1 n );       return 0;     }     unsigned long long l = lcm(w, b);     if (l <= 0)       p = mi - 1;     else {       unsigned long long x = t / l;       if (x == 0) {         p = mi - 1;       } else {         p = min(mi, t - x * l + 1) + x * mi - 1;       }     }     unsigned long long d = gcd(p, t);     printf( %lld/%lld n , p / d, t / d);     return 0;   }   