B"Of course, many of you can calculate xcf x86(n) -- the number of positive integers that are less than or equal to n, that are coprime with n. But what if we need to calculate xcf x86( xcf x86(... xcf x86(n))), where function xcf x86 is taken k times and n is given in the canonical decomposition into prime factors? You are given n and k, calculate the value of xcf x86( xcf x86(... xcf x86(n))). Print the result in the canonical decomposition into prime factors. The first line contains integer m (1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89m xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89105) -- the number of distinct prime divisors in the canonical representaion of n. Each of the next m lines contains a pair of space-separated integers pi, xe2 x80 x89ai (2 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89pi xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89106; 1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89ai xe2 x80 x89 xe2 x89 xa4 xe2 x80 x891017) -- another prime divisor of number n and its power in the canonical representation. The sum of all ai doesn't exceed 1017. Prime divisors in the input follow in the strictly increasing order. The last line contains integer k (1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89k xe2 x80 x89 xe2 x89 xa4 xe2 x80 x891018). In the first line, print integer w -- the number of distinct prime divisors of number xcf x86( xcf x86(... xcf x86(n))), where function xcf x86 is taken k times. Each of the next w lines must contain two space-separated integers qi, xe2 x80 x89bi (bi xe2 x80 x89 xe2 x89 xa5 xe2 x80 x891) -- another prime divisor and its power in the canonical representaion of the result. Numbers qi must go in the strictly increasing order. You can read about canonical representation of a positive integer here: http://en.wikipedia.org/wiki/Fundamental_theorem_of_arithmetic. You can read about function xcf x86(n) here: http://en.wikipedia.org/wiki/Euler's_totient_function."...