各路神仙帮帮蒟蒻吧

#include<bits/stdc++.h>
using namespace std;
using gg=long long;
gg ni,mi;
gg res=0;
void dfs(gg start,gg current)
{
    if(current==mi&&start==0)
    {
        res+=1;
        return;
    }
    else if(current>mi)
    {
        return;
    }
    else
    {
        dfs((start+1+ni)%ni,current+1);
        dfs((start-1+ni)%ni,current+1);
    }

}
int main()
{
    cin>>ni>>mi;
    dfs(0,0);
    cout<<res<<endl;
    return 0;
}