/** thelo na emfaniso meso oro apo dekadikous
se ena arxeio alla se kathe grammi mporei na yparxoyn
kai alloi xaraktires **/

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

/** epistrefei 1 an exei mesa mono noumera 
 * kai ton diaxoristi .**/
int alldigits(char x[])
{
	int i;
	for(i=0;i<strlen(x);i++)
	{
		if(!(x[i]>='0' && x[i]<='9') && x[i]!='.') return 0;
	}
	return 1;
}

int main()
{
	FILE *fp;
	char line[100];
	double x;
	double sum = 0;
	int total = 0;
	fp=fopen("number.txt","r");
/*	while(fscanf(fp,"%lf",&x)>0)
	{
		total++;
		sum=sum+x;
	}*/
	while(fgets(line,99,fp)!=NULL)
	{
		if(line[strlen(line)-1]=='\n')
		  line[strlen(line)-1]='\0';
		if(alldigits(line))  //atof(), atoi()
		{
			 x= atof(line);
			 total++;
			 sum=sum+x;
		}
	}
	printf("Average: %lf \n",sum/total);
	fclose(fp);
	return 0;
}