SP2415 RESIST - Kirchhof Law

Description

N/A

Input Format

Multiple test cases. For each test case: The first line contains integers N and M; N is a number of nodes in the circuit (2 < N

Output Format

For each test case, output the total resistance between the nodes 1 and N rounded within two digits after a decimal points. There won't be any test case the output for which is +INF.