Compilare: main.c: In function 'invmod': main.c:20:7: warning: unused variable 'a' [-Wunused-variable] int a=exprap(x,MOD-2); ^ main.c:23:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ main.c: In function 'main': main.c:30:3: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d%d",&a,&b); ^~~~~~~~~~~~~~~~~~~~~~~~