Chemistry

Time limit2sMemory limit1024 MB

Summary

Given a chemical formula with C, H, N, O and counts, the task is to print the total molar mass using fixed atomic weights.

Level: Easy2 of 10
Topics: String, Implementation, Simulation
Solved: No attempts yet

Problem

Your task is to compute the mass of a molecule given by its chemical formula. The formula is a list of the elements in the molecule. The notation $E n$ means that element $E$ is repeated $n$ times. The mass of a molecule is the sum of the weights of all its elements.

Element name	Symbol	Mass
Hydrogen	H	1
Carbon	C	12
Nitrogen	N	14
Oxygen	O	16

The input file has one line containing the formula. The formula is at most 20 characters long. It consists of the letters C, H, N, O and the digits 1 to 9. A digit always follows a letter.

Output

Print one number to the output file: the mass of the molecule.

Examples2

Example 1
Input
```
H2O
```
Expected output
```
18
```
Example 2
Input
```
C3H5NO3NO3NO3
```
Expected output
```
227
```