Summation of weight of each character in this String

Consider All lowercase Alphabets of the English language. Here we consider each alphabet from a to z to have a certain weight. The weight of the alphabet a is considered to be 1, b to be 2, c to be 3 and so on until z has a weight of 26. In short, the weight of the alphabet a is 1, and the weight of all other alphabets is the weight of its previous alphabet + 1.
Now, you have been given a String S consisting of lowercase English characters. You need to find the summation of weight of each character in this String.
For example, Consider the String aba
Here, the first character a has a weight of 1, the second character b has 2 and the third character a again has a weight of 1. So the summation here is equal to : 1+2+1=4
Input Format:
The first and only line of input contains the String S.
Output Format:
Print the required answer on a single line
Constraints:
1≤|S|≤100

SAMPLE INPUT

aba

SAMPLE OUTPUT

4

Explanation
Value of a is 1 and b is 2 
aba --> 1+2+1=4
Hence the output is 4

                                                          C Solution

#include<stdio.h>

int main()

{

int n,i,c;

char s[100];

scanf("%s",s);

n = strlen(s);

int z = 0;

for(i=0;i<n;i++)

{

c = s[i] - 96;

z=z+c;

}

printf("%d",z);

return 0;

}