#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
string a="1",b="1",c="1";
int A[255],B[255],C[255];
string add(string a,string b){
    memset(A,0,sizeof A);
    memset(B,0,sizeof B);
    memset(C,0,sizeof C);
    for (int i=a.size(),j=0;i>=1;--i,++j){A[j]=a[i-1]^48;}
    for (int i=b.size(),j=0;i>=1;--i,++j){B[j]=b[i-1]^48;}
    int sss=max(a.size(),b.size())+1;
    for (int i=0;i<=sss;++i){
        C[i]+=A[i]+B[i];C[i+1]+=C[i]/10;C[i]%=10;
    }
    bool ok=0;
    string ans="";
    for (int i=sss;~i;--i){ok|=C[i];if (ok){ans+=(char)(C[i]^48);}}
    return (ans.size())?ans:"0";
}
int main(){
    int n,m;
    scanf("%d%d",&n,&m);
    if (n==m||(n+1==m)){return putchar('1'),0;}
    for (int i=n+2;i<=m;++i){
        c=add(a,b);
        a=b;
        b=c;
    }
    puts(c.c_str());
    return 0;
}