怎么肥四！AC3个，WA3个，剩下的全TLE

#include<bits/stdc++.h>
using namespace std;
long long n,m,cnt=1,x=1,y=1,z=1;
int main(){
	scanf("%lld %lld",&n,&m);
	if(n<=2){
		cout<<1;
		return 0;
	}
	while(cnt<=n-2){
		x=(y+z)%m;
		cnt++;
		if(cnt>n-2){
			printf("%lld",x);
			break;
		}
		y=(x+z)%m;
		cnt++;
		if(cnt>n-2){
			printf("%lld",y);
			break;
		} 
		z=(x+y)%m;
		cnt++;
		if(cnt>n-2){
			printf("%lld",z);
			break;
		}
	}
	return 0;
}