#include<iostream>
#include<vector>
#include<atcoder/math>
using namespace std;
int F[1<<20];
pair<long,int>f(long N,int p)
{
	pair<long,int>ret=make_pair(0,1);
	while(N>=1)
	{
		long q=N/p,r=N%p;
		ret.second=(long)ret.second*atcoder::pow_mod(F[p-1],q,p)%p*F[r]%p;
		ret.first+=N=q;
	}
	return ret;
}
pair<long,int>mul(pair<long,int>ret,long v,int p)
{
	while(v%p==0)v/=p,ret.first++;
	ret.second=(long)ret.second*(v%p)%p;
	return ret;
}
int main()
{
	long L,R;int M;
	cin>>L>>R>>M;
	vector<pair<int,int> >fac;
	{
		int m=M;
		for(int i=2;i*i<=m;i++)if(m%i==0)
		{
			fac.push_back(make_pair(i,0));
			while(m%i==0)m/=i,fac.back().second++;
		}
		if(m>1)fac.push_back(make_pair(m,1));
	}
	vector<long long>r,m;
	for(pair<int,int>fp:fac)
	{
		int p=fp.first,mod=1;
		for(int i=0;i<fp.second;i++)mod*=p;
		F[0]=1;
		for(int i=1;i<p;i++)F[i]=(long)F[i-1]*i%p;
		m.push_back(mod);
		int now=0;
		pair<long,int>x=f(2*L,p),y=f(L,p);
		for(long n=L;n<=R;n++)
		{
			if(n>L)
			{
				//x <- 2*n-1,2*n
				//y <- n
				x=mul(mul(x,2*n-1,p),2*n,p);
				y=mul(y,n,p);
			}
			int tmp=(long)x.second*atcoder::inv_mod((long)y.second*y.second%p,p)%p;
			assert(x.first-y.first*2>=0);
			if(x.first-y.first*2>=fp.second)tmp=0;
			else
			{
				for(int i=0;i<x.first-y.first*2;i++)tmp=(long)tmp*p%mod;
			}
			now=(now+tmp)%mod;
		}
		r.push_back(now);
	}
	long ans=atcoder::crt(r,m).first;
	ans=(ans-(R-L+1)*2%M+M)%M;
	cout<<ans<<endl;
}