#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <utility>
#include <queue>
#include <string>
#include <cstring>
#include <map>
using namespace std;
#define in cin
#define out cout
#define ll long long int
ll DV = 1000000007;
ll pow(ll a, ll b)
{
ll t = a;
ll res = 1;
while(b)
{
if(b%2) res = (res * t) % DV;
t = t % DV;
t = (t*t) % DV;
b = b >> 1;
}
return res;
}
ll inv(ll a)
{
return pow(a, DV-2)%DV;
}
ll mul(ll a, ll b)
{
return (a%DV)*(b%DV)%DV;
}
struct mat22
{
ll a1, a2, a3, a4;
mat22 operator*(const mat22 &T)
{
return {mul(a1, T.a1)+mul(a2, T.a3), mul(a1, T.a2)+mul(a2, T.a4),
mul(a3, T.a1)+mul(a4, T.a3), mul(a3, T.a2)+mul(a4, T.a4)};
}
void print()
{
out << a1 << " " << a2 << " " << a3 << " " << a4 << endl;
}
};
int main()
{
ll A, B; in >> A >> B;
B = A-B;
ll p = B*inv(A);
ll q = (A-B)*inv(A);
mat22 T = {inv(p), mul(-q, inv(p)) + DV, 1, 0};
ll N, K; in >> N >> K;
ll a1, a2, a0 = 0;
mat22 MT = {1,0,0,1};
for(int i=2; i<=N; i++)
{
MT = MT * T;
}
a1 = inv(MT.a1);
if(K == 0) out << 0;
else if(K == N) out << 1;
else
{
for(int i=1; i<K; i++)
{
a2 = mul( T.a1, a1 ) + mul( T.a2, a0 );
a2 %= DV;
a0 = a1 % DV;
a1 = a2 % DV;
}
out << a1;
}
return 0;
}
