F. Geometrical Progressiontime limit per test4 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputFor given n, l and r find the number of distinct geometrical progression, each of which contains n distinct integers not less than l and not greater than r. In other words, for each progression the following must hold: l ≤ ai ≤ r and ai ≠ aj , where a1, a2, ..., an is the geometrical progression, 1 ≤ i, j ≤ n and i ≠ j.Geometrical progression is a sequence of numbers a1, a2, ..., an where each term after first is found by multiplying the previous one by a fixed non-zero number d called the common ratio. Note that in our task d may be non-integer. For example in progression 4, 6, 9, common ratio is .Two progressions a1, a2, ..., an and b1, b2, ..., bn are considered different, if there is such i (1 ≤ i ≤ n) that ai ≠ bi.InputThe first and the only line cotains three integers n, l and r (1 ≤ n ≤ 107, 1 ≤ l ≤ r ≤ 107).OutputPrint the integer K — is the answer to the problem.ExamplesInput1 1 10Output10Input2 6 9Output12Input3 1 10Output8Input3 3 10Output2NoteThese are possible progressions for the first test of examples:   1;  2;  3;  4;  5;  6;  7;  8;  9;  10. These are possible progressions for the second test of examples:   6, 7;  6, 8;  6, 9;  7, 6;  7, 8;  7, 9;  8, 6;  8, 7;  8, 9;  9, 6;  9, 7;  9, 8. These are possible progressions for the third test of examples:   1, 2, 4;  1, 3, 9;  2, 4, 8;  4, 2, 1;  4, 6, 9;  8, 4, 2;  9, 3, 1;  9, 6, 4. These are possible progressions for the fourth test of examples:   4, 6, 9;  9, 6, 4. 
Input1 1 10
Output10
['brute force', 'math', 'number theory', '*2400']