#include<cstdio>

#include<cstdlib>

#include<iostream>

#include<fstream>

#include<algorithm>

#include<cstring>

#include<string>

#include<cmath>

#include<queue>

#include<stack>

#include<map>

#include<utility>

#include<set>

#include<bitset>

#include<vector>

#include<functional>

#include<deque>

#include<cctype>

#include<climits>

#include<complex>

//#include<bits/stdc++.h>适用于CF,UOJ，但不适用于poj

using namespace std;

typedef unsigned long long ULL;

typedef long long LL;

typedef double DB;

typedef pair<int,int> PII;

typedef complex<DB> CP;

#define mmst(a,v) memset(a,v,sizeof(a))

#define mmcy(a,b) memcpy(a,b,sizeof(a))

#define fill(a,l,r,v) fill(a+l,a+r+1,v)

#define re(i,a,b)  for(i=(a);i<=(b);i++)

#define red(i,a,b) for(i=(a);i>=(b);i--)

#define ire(i,x) for(typedef(x.begin()) i=x.begin();i!=x.end();i++)

#define fi first

#define se second

#define m_p(a,b) make_pair(a,b)

#define SF scanf

#define PF printf

#define two(k) (1<<(k))

template<class T>inline T sqr(T x){return x*x;}

template<class T>inline void upmin(T &t,T tmp){if(t>tmp)t=tmp;}

template<class T>inline void upmax(T &t,T tmp){if(t<tmp)t=tmp;}

const DB EPS=1e-;

inline int sgn(DB x){if(abs(x)<EPS)return ;return(x>)?:-;}

const DB Pi=acos(-1.0);

inline int gint()

  {

        int res=;bool neg=;char z;

        for(z=getchar();z!=EOF && z!='-' && !isdigit(z);z=getchar());

        if(z==EOF)return ;

        if(z=='-'){neg=;z=getchar();}

        for(;z!=EOF && isdigit(z);res=res*+z-'',z=getchar());

        return (neg)?-res:res;

    }

inline LL gll()

  {

      LL res=;bool neg=;char z;

        for(z=getchar();z!=EOF && z!='-' && !isdigit(z);z=getchar());

        if(z==EOF)return ;

        if(z=='-'){neg=;z=getchar();}

        for(;z!=EOF && isdigit(z);res=res*+z-'',z=getchar());

        return (neg)?-res:res;

    }

const ULL Mod=;

ULL b,d,n;

ULL res;

inline ULL cheng(ULL a,ULL b)

  {

      ULL res=;

      for(;b!=;b>>=){if(b&)res=(res+a)%Mod;a=(a<<)%Mod;}

      return res;

  }

struct Tmatrix

  {

      int n,m;

      ULL v[][];

      inline void clear(){n=m=;mmst(v,);}

      inline friend Tmatrix operator *(Tmatrix a,Tmatrix b)

        {

            Tmatrix c;c.clear();

            int i,j,k;

            c.n=a.n;c.m=b.m;

            re(i,,c.n)

                  re(j,,c.m)

                      re(k,,a.m)

                          c.v[i][j]=(c.v[i][j]+cheng(a.v[i][k],b.v[k][j]))%Mod;

                return c;

        }

  };

inline Tmatrix power(Tmatrix a,ULL k)

  {

      Tmatrix x;x.clear();

        x.n=x.m=;

        x.v[][]=x.v[][]=;

        while(k){if(k&)x=x*a;a=a*a;k>>=;}

        return x;

  }

Tmatrix A;

int main()

  {

      freopen("bzoj4002.in","r",stdin);

      freopen("bzoj4002.out","w",stdout);

      b=gll();d=gll();n=gll();

      if(n==)

        cout<<""<<endl;

      else

        {

            A.clear();

            A.n=A.m=;

            A.v[][]=b;A.v[][]=(d-b*b)/;

            A.v[][]=;A.v[][]=;

            A=power(A,n-);

            res=(cheng(A.v[][],b)+cheng(A.v[][],))%Mod;

                if(b*b!=d && !(n&))res--;

                res=(res%Mod+Mod)%Mod;

                cout<<res<<endl;

        }

      return ;

  }