1234

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>

int main(void)
{   char str[6];
    int j, n;
    int x=1, d, flag, i;

    printf("\n Please note i'm working with maximum of 4 digits number!");
    printf("\n Please type N: ");
    fgets( str, 6, stdin );
        if (str[0] == '0')
        {
            printf("\n Error - zero or symbol at start!");
            return -1;
        }
        for (j = 0; str[j] != '\n'; j++)
        {
            if (isdigit(str[j]) == 0)
            {
                printf("\n Error - you are trying to use symbols!");
                printf("\n OR you are entering too much!");
                return -1;
            }
            else
                continue;
        }
    for (j = 1; j <= 4; j++)
    {
        if ( str[j] == '\n' )
        {
            str[j] = 'y';
            break;
        }
    }
    n=atoi(str);
   printf("\n I guess you typed %d !", n);
   while(i!=n)
    {
        x++;
        flag=1;
        for(d=2;d<x;d++)
        {
            if (x%d==0)
            {
                flag=0;
                break;
            }
        }
        if(flag)
	    {
            printf("%d\n",x);
	         i++;
	    }
    }
    return 0;
}