Fountains

There is a garden of length 105 having range x=1 to x=105. There are n number of fountains. Fountain i has range x = l[i] to x = r[i] and drops 1 gallon of water per unit. Bob turns on fountains, trying every subset of Power set(See example for more clarity). Find the total gallons of water mod 109 + 7 given by fountains. Input - The first line of the input contains a single integer n denoting