#include <stdio.h>
#include <cs50.h>
#include <string.h>
#include <ctype.h>
#include <math.h>

int main(int argc, string argv[])
{
    string s = get_string("Input: "); //get user input
    float lc = 0;//lettercount
    float wc = 0;//wordcount
    float sc = 0;//sentencecount

    for (int i = 0; i < strlen(s); i++)
    {
        if (isalpha(s[i]))
        {
            lc++;
        }
        if (isspace(s[i]) && !isspace(s[i + 1]))
        {
            wc++;
        }

        if (s[i] == '.' || s[i] == '!' || s[i] == '?')
        {
            sc++;
        }
    }

    wc++;

    float L = lc / wc * 100;//letters per hundred words
    float S = sc / wc * 100;//sentences per hundred words

    float index = 0.0588 * L - 0.296 * S - 15.8;

    if (round(index) < 1)
    {
        printf("Before Grade 1\n");
    }
    else
    {

        if (round(index) >= 16)
        {
            printf("Grade 16+\n");
        }
        else
        {
            printf("\n");
            printf("Grade %i\n", (int)round(index));
        }
    }
}