import java.math.BigInteger;

import java.util.Scanner;

public class Main {

    public static BigInteger GCD(BigInteger a,BigInteger b)

    {

        if(b.equals(BigInteger.ZERO)) return a;

        return GCD(b,a.mod(b));

    }

    public static void main(String [] args)

    {

        Scanner cin = new Scanner(System.in);

        int M,N,L;

        BigInteger c[][] = new BigInteger[105][105];

        BigInteger dp[][] = new BigInteger[105][105];

        for(int i=0;i<=100;i++)  c[i][0] = c[i][i] = BigInteger.ONE;

        for(int i=1;i<=100;i++)

        {

            for(int j=1;j<i;j++)

            {

                c[i][j]= c[i-1][j-1].add(c[i-1][j]);

            }

            for(int j=i+1;j<=100;j++) c[i][j] = BigInteger.ZERO;

        }

        while(cin.hasNext())

        {

            M=cin.nextInt();

            N=cin.nextInt();

            L=cin.nextInt();

            if(L>M) System.out.println("mukyu~");

            else

            {

                BigInteger n = BigInteger.valueOf(N);

                BigInteger fm = n.pow(M);

                BigInteger fz = new BigInteger("0");

                for(int i=0;i<=N;i++)

                {

                    for(int j=0;j<=M;j++)

                    {

                        dp[i][j] = BigInteger.ZERO;

                    }

                }

                dp[0][0] = BigInteger.ONE;

                for(int i=1;i<=N;i++)

                {

                    for(int j=0;j<=M;j++)

                    {

                        for(int k=0;k<=L-1;k++)

                        {

                            if(j-k<0) continue;

                            if(M-(j-k)<0) continue;

                            dp[i][j] = dp[i][j].add(dp[i-1][j-k].multiply(c[M-(j-k)][k]));

                        }

                    }

                }

                fz=dp[N][M]; fz = fm.subtract(fz);

                BigInteger gcd = GCD(fz,fm);

                fz=fz.divide(gcd); fm=fm.divide(gcd);

                System.out.println(fz+"/"+fm);

            }

        }

    }

}