# PROBLEM LINK:

* Author:* Himanshu

# DIFFICULTY:

EASY

# PREREQUISITES:

# EXPLANATION:

Replace vowels with 1 and consonants with 0. you will get a binary string. For eg hello will become 01001.

Now the problem reduces to binary to decimal conversion.

Approach for binary to decimal conversion:

16 8 4 2 1

0 1 0 0 1

n = length of string

Initialize the answer to 0.

Iterate over the string

Whenever you get 1 in the binary string you need to calculate pow(2, n-i-1) , where i is the i^{th} index from the start and add it to the answer.

At each step whenever there is 1 in the binary string you need to compute power of 2. Since this can be very large. we compute it modulo 10^{9}+7. For this we use modular exponentiation.

### COMPLEXITY:

O(nlogn)