#include <stdio.h>
#include <stdbool.h>  //This is to bring in the define of true

#include <math.h>  //This is to bring in the define of sqrt()

int main (int argc, const char * argv[]) {
    bool    isPrime;
    int     startingPoint, candidate, last, i;

    startingPoint = 100;

    if ( startingPoint <= 2 ) {
        candidate = 3;
    }
    else {
        candidate = startingPoint;
        if (candidate % 2 == 0)             // Test only odd numbers
            candidate--;
        do {
            isPrime = true;                 // Assume glorious success
            candidate += 2;                 // Bump to the next number to test
            last = sqrt( candidate );       // We'll check to see if candidate
                                            // has any factors, from 3 to last
                                            // Loop through odd numbers only
            for ( i = 3; (i <= last) && isPrime; i += 2 ) {
                if ( (candidate % i) == 0 )
                    isPrime = false;
            }
        } while ( ! isPrime );
    }



    printf( "The next prime after %d is %d. Happy?\n",
           startingPoint, candidate );
    return 0;
}