Exactly solvable small-world network

We present an exact description of a crossover between two different regimes of simple small-world networks. Each of the sites chosen with a probability p from n sites of an ordered system defined on a circle is connected to all other sites selected in such a way. Every link is of a unit length. While p changes from 0 to 1, an averaged shortest distance between a pair of sites changes from (l) over bar similar to n to (l) over bar = 1. We find the distribution of the shortest distances P(l) and obtain a scaling form of (l) over bar(p, n). In spite of the simplicity of the models under consideration, the results are close to those obtained numerically for usual small-world networks.