//ACSL 2006-07

//Intermediate, Contest #1

//PROBABILITY

//By Jacob Plachta, Grade 9

#include <iostream>

#include <string>

#include <stdio.h>

int main()

{

//Vars

int nod,nor,nob,den,num;

char rep,ev1,ev2;

//Test-case Loop

for (int xxx=1; xxx<=5; xxx++)

{

//Input and compute probability

scanf("%d",&nod);

scanf("%d",&nor);

scanf("%d",&nob);

scanf("%d",&ev1);

if (nod==1)

{

scanf("%c",&ev1);

if ((ev1=='R') || (ev1=='b'))

num=nor;

else

num=nob;

den=nor+nob;

}

else

{

scanf("%c",&rep);

scanf("%c",&ev1);

scanf("%c",&ev1);

scanf("%c",&ev2);

scanf("%c",&ev2);

if (ev1=='r') ev1='B';

if (ev1=='b') ev1='R';

if (ev2=='r') ev2='B';

if (ev2=='b') ev2='R';

if (ev1=='R')

num=nor;

else

num=nob;

den=nor+nob;

if (rep=='N')

if (ev1=='R')

nor--;

else

nob--;

if (ev2=='R')

num*=nor;

else

num*=nob;

den*=nor+nob;

}

//Output

printf("\n%d/%d\n\n",num,den);

}

return(0);

}