import std.conv, std.functional, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.complex, std.container, std.math, std.numeric, std.range, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }




void main() {
  try {
    for (; ; ) {
      const T1 = readLong();
      const T2 = readLong();
      const T3 = readLong();
      
      long p2 = T1 * T2;
      long q2 = T2 - T1;
      const g2 = gcd(p2, q2);
      p2 /= g2;
      q2 /= g2;
      
      long p3 = T1 * T3;
      long q3 = T3 - T1;
      const g3 = gcd(p3, q3);
      p3 /= g3;
      q3 /= g3;
      
      const p = p2 / gcd(p2, p3) * p3;
      const q = gcd(q2, q3);
      writefln("%s/%s", p, q);
    }
  } catch (EOFException e) {
  }
}