The geometric progession is the sequence of numbers 1, a, a^2, a^3 etc. For example, for a = 3, the first few elements of the geometric progression will be 1, 3, 9, 27, 81... Given number a, calculate sum of first b elements of the corresponding geometric progression modulo 1000000007. Input data specification The only lie cotains two numbers: a and b 2 <= a <= 100 1 <= b <= 1000000000 (10^9) Output data specification Output the requested value. Sample input: 3 3 Sample output: 13 Note: First three elements for a=3 are 1, 3 and 9 Their sum is 1+3+9 = 13.