National Olympiad in Informatics, China, 2013
TingTing is a girl that loves matrices. One day, she wants to use a
computer to generate a giant 
~n~ row by 
~m~ column matrix (you don't
have to worry about how she'll store it). Her generated matrix will
satisfy a mystical property: if we use 
~F[i][j]~ to represent the
cell in the 
~i~-th row and 
~j~-th column, then 
~F[i][j]~ will
satisfy the following system of equations:
$$\displaystyle \begin{cases}
F[1][1] = 1 \\
F[i][j] = a \times F[i][j-1]+b && j \ne 1 \\
F[i][1] = c \times F[i-1][m]+d && i \ne 1
\end{cases}$$
where 
~a~, 
~b~, 
~c~, and 
~d~ are given constants.
TingTing would like to know the value of 
~F[n][m]~ and she would
like you to help her. Since the final value may be very large, you are
only required to output it modulo 
~1\,000\,000\,007~.
Input Specification
The input will contain the six integers 
~n~, 
~m~, 
~a~, 
~b~, 
~c~, and
~d~.
Output Specification
Output a single integer, the value of 
~F[n][m]~ modulo
~1\,000\,000\,007~.
Sample Input
3 4 1 3 2 6
Sample Output
85
Explanation
The matrix in the example is:
$$\displaystyle \begin{pmatrix} 1 & 4 & 7 & 10 \\ 26 & 29 & 32 & 35 \\ 76 & 79 & 82 & 85 \end{pmatrix}$$
Constraints
| Test Case | 
Constraints | 
| 1 | 
 ~1 \le n, m \le 10~;  ~1 \le a, b, c, d \le 1\,000~ | 
| 2 | 
 ~1 \le n, m \le 100~;  ~1 \le a, b, c, d \le 1\,000~ | 
| 3 | 
 ~1 \le n, m \le 10^3~;  ~1 \le a, b, c, d \le 10^9~ | 
| 4 | 
| 5 | 
 ~1 \le n, m \le 10^9~;  ~1 \le a = c \le 10^9~;  ~1 \le b = d \le 10^9~ | 
| 6 | 
 ~1 \le n, m \le 10^9~;  ~a = c = 1~;  ~1 \le b, d \le 10^9~ | 
| 7 | 
 ~1 \le n, m, a, b, c, d \le 10^9~ | 
| 8 | 
| 9 | 
| 10 | 
| 11 | 
 ~1 \le n, m \le 10^{1\,000}~;  ~a = c = 1~;  ~1 \le b, d \le 10^9~ | 
| 12 | 
 ~1 \le n, m \le 10^{1\,000}~;  ~1 \le a = c \le 10^9~;  ~1 \le b = d \le 10^9~ | 
| 13 | 
 ~1 \le n, m \le 10^{1\,000}~;  ~1 \le a, b, c, d \le 10^9~ | 
| 14 | 
| 15 | 
 ~1 \le n, m \le 10^{20\,000}~;  ~1 \le a, b, c, d \le 10^9~ | 
| 16 | 
| 17 | 
 ~1 \le n, m \le 10^{1\,000\,000}~;  ~a = c = 1~;  ~1 \le b, d \le 10^9~ | 
| 18 | 
 ~1 \le n, m \le 10^{1\,000\,000}~;  ~1 \le a = c \le 10^9~;  ~1 \le b = d \le 10^9~ | 
| 19 | 
 ~1 \le n, m \le 10^{1\,000\,000}~;  ~1 \le a, b, c, d \le 10^9~ | 
| 20 | 
Problem translated to English by Alex.
 
                    
             
        
Comments
Since the original data were weak, two additional test cases were added and weighted identically to the others, and all submissions were rejudged.