`random' undeclared (first use this function) - C (СИ)

# include <stdio.h>
# include <stdlib.h>
# include <conio.h>
 
const int N=10;
 
main () {
     int i, A[N];
     for (i=0; i<N; i++)
         A[i]=random(26)-10;
     
     printf("The first massive is: ");
     
     for (i=0; i<N; i++)
         printf("%d", A[i]);
     
     for (i=0; i<N; i++)
         A[i]=A[i]*2;
     
     printf("The result is: ");
     
     for (i=0; i<N; i++)
         printf ("%d", A[i]);
getch();     
}

# include <stdio.h>
# include <conio.h>
 
const int N=10;
 
main(){
       int i, A[N];
       FILE *fp;
       fp = fopen("D:\\input.dat", "r");
       if (fp==NULL) {
         printf("No file");
         return 1;               
         }
       for (i=0; i<N; i++)
           if (0== fscanf(fp,"%d", &A[i])) {
                   printf ("Not enought data!!");
                   break;
                   }
       fclose (fp);
       for (i=0; i<N; i++)
           A[i] = A[i]*2;
       fp = fopen ("output.dat", "w");
       for (i=0; i<N; i++)
           fpintf(fp, "%d\n", A[i]);
       fclose(fp);
}

fpintf(fp, "%d\n", A[i]);