我的代码

#include <bits/stdc++.h>
//#define re register
//typedef unsigned long long uint;
//typedef long long int;

#define int long long
using namespace std;
long long a[3];
signed main() {
	long long n,p;
	scanf("%lld%lld",&n,&p);
	a[1]=1;
	a[2]=1;
	if(n>150000000)
		n=n%150000000;
	for(long long i=3;i<=n;i++)
		a[i%3]=((a[(i-1)%3]%p)+a[(i-2)%3]%p)%p;
	printf("%lld\n",a[n%3]%p);
	return 0;
}