Compilare: user.c: In function ‘main’: user.c:13:1: warning: passing argument 2 of ‘fprintf’ makes pointer from integer without a cast [enabled by default] fprintf(file2, 2*N/7); ^ In file included from /usr/include/stdio.h:934:0, from user.c:1: /usr/include/i386-linux-gnu/bits/stdio2.h:96:1: note: expected ‘const char * restrict’ but argument is of type ‘int’ fprintf (FILE *__restrict __stream, __const char *__restrict __fmt, ...) ^ user.c:12:7: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%d", &N); ^