#include <iostream>
#include <algorithm>

using namespace std;

long long gcd(long long x, long long y) {
	do {
		if (x < y) {
			swap(x, y);
		}
		x = x % y;
	} while (x > 0LL);
	return y;
}

long long lcm(long long x, long long y) {
	return x * y / gcd(x, y);
}

int main() {
	long long t[3];
	cin >> t[0] >> t[1] >> t[2];
	long long multiple = lcm(t[0], lcm(t[1], t[2]));
	long long denominator;
	long long positions[3];
	for (denominator = min(multiple, 1000000LL); denominator >= 0; --denominator) {
		for (int i = 0; i < 3; ++i) {
			positions[i] = 2 * multiple / t[i] % (2 * denominator);
			if (positions[i] > denominator) {
				positions[i] = 2 * denominator - positions[i];
			}
		}
		if (positions[0] == positions[1] && positions[1] == positions[2]) {
			break;
		}
	}
	long long divisor = gcd(multiple, denominator);
	multiple /= divisor;
	denominator /= divisor;
	cout << multiple << "/" << denominator << endl;
	return 0;
}