Compilare: main.c:3:6: warning: return type of 'main' is not 'int' [-Wmain] void main () { ^~~~ main.c: In function 'main': main.c:10:18: warning: unused variable 'm2' [-Wunused-variable] int n,p,q,m1,m2,s=0; ^~ main.c:10:15: warning: unused variable 'm1' [-Wunused-variable] int n,p,q,m1,m2,s=0; ^~ main.c:11:5: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf (f_in,"%d", &n); ^~~~~~~~~~~~~~~~~~~~~~