http://120.78.162.102/problem.php?cid=1432&pid=8

http://120.78.162.102/problem.php?id=6250

题解：DFS

/*
*@Author:   STZG
*@Language: C++
*/
#include <bits/stdc++.h>
#include<iostream>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<string>
#include<vector>
#include<bitset>
#include<queue>
#include<deque>
#include<stack>
#include<cmath>
#include<list>
#include<map>
#include<set>
//#define DEBUG
#define RI register int
using namespace std;
typedef long long ll;
//typedef __int128 lll;
const int N=10000;
const int MOD=1e9+7;
const double PI = acos(-1.0);
const double EXP = 1E-8;
const int INF = 0x3f3f3f3f;
int t,n,m,k,q,ans;
void dfs(int a,int b,int c,int d){
    if(b>=n+m){
        if(a==0)
            ans++;
        return;
    }
    if(a<=0)
        return;
    if(d<n)
        dfs(a-1,b+1,c,d+1);
    if(c<m)
        dfs(a*2,b+1,c+1,d);
}
int main()
{
#ifdef DEBUG
	freopen("input.in", "r", stdin);
	//freopen("output.out", "w", stdout);
#endif
    scanf("%d%d",&m,&n);
    dfs(2,0,0,0);
    cout << ans << endl;
    //cout << "Hello world!" << endl;
    return 0;
}