/*
ye mera template hai
apna khud likho bc :P
*/
/*
Author : Sarvagya Agarwal
*/
#include<bits/stdc++.h>
using namespace std;
//defines
#define openin freopen("input.txt","r",stdin)
#define openout freopen("output.txt","w",stdout)
#define fast ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#define ll long long
#define int long long
#define mod 1000000007
#define rep(i,x,y) for (__typeof(x) i=x;i<=y;i++)
#define all(c) (c).begin(),(c).end()
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
/* Print pair */
template <typename T,typename S>
ostream & operator << (ostream &os , const pair<T,S> &v) {
os << "(" ;
os << v.first << "," << v.second << ")" ;
return os ;
}
/* Print vector */
template <typename T>
ostream & operator << (ostream &os , const vector<T> &v) {
os << "[" ;
int sz = v.size() ;
for(int i = 0 ; i < sz ; ++i) {
os << v[i] ;
if(i!=sz-1)os << "," ;
}
os << "]\n" ;
return os ;
}
/* Print set */
template <typename T>
ostream & operator << (ostream &os , const set<T> &v) {
T last = *v.rbegin() ;
os << "[" ;
for(auto it : v) {
os << it ;
if(it != last) os << "," ;
}
os << "]\n" ;
return os ;
}
/* Print Map */
template <typename T,typename S>
ostream & operator << (ostream &os , const map<T,S> &v) {
for(auto it : v) {
os << it.first << " : " << it.second << "\n" ;
}
return os ;
}
int power(int a , int b)
{
int res = 1 ;
while(b)
{
if(b%2) {
res = (res * a)%mod ;
}
b/=2 ;
a = (a*a)%mod ;
}
return res ;
}
//debug
#define TRACE
#ifdef TRACE
#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1>
void __f(const char* name, Arg1&& arg1){
cerr << name << " : " << arg1 << std::endl;
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args){
const char* comma = strchr(names + 1, ',');cerr.write(names, comma - names) << " : " << arg1<<" | ";__f(comma+1, args...);
}
#else
#define trace(...)
#endif
int n , k ;
int dp[65][65][65] ;
int solve(int index, int cnt , int max_cnt)
{
//trace(index,cnt,max_cnt);
if(index > n) {
return max_cnt>=k ;
}
if(dp[index][cnt][max_cnt] != -1)
return dp[index][cnt][max_cnt] ;
int res = 0 ;
// A
res += solve(index+1,0,max_cnt) ;
// B
res += solve(index+1,cnt+1,max(max_cnt,cnt+1)) ;
return dp[index][cnt][max_cnt] = res ;
}
int32_t main()
{
fast;
memset(dp,-1,sizeof(dp));
cin >> n >> k ;
int num = solve(1,0,0) ;
int den = (1<<n) ;
int g = __gcd(num,den) ;
num /= g ;
den /= g ;
cout << num << '/' << den << '\n' ;
return 0;
}
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