Compilare: main.c: In function 'main': main.c:14:9: warning: this 'for' clause does not guard... [-Wmisleading-indentation] for(i = n1; i>=2; --i); ^~~ main.c:15:13: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for' if(n1 % i == 0 && n2 % i == 0){ ^~ main.c:5:15: warning: variable 'g' set but not used [-Wunused-but-set-variable] FILE *f, *g; ^ main.c:9:5: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &n1); ^~~~~~~~~~~~~~~~~~~~ main.c:10:5: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &n2); ^~~~~~~~~~~~~~~~~~~~ main.c:15:34: warning: 'i' may be used uninitialized in this function [-Wmaybe-uninitialized] if(n1 % i == 0 && n2 % i == 0){ ~~~^~~