Compilare: user.cpp: In function ‘int main()’: user.cpp:3:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] int main(){freopen("dirichlet.in","r",stdin);freopen("dirichlet.out","w",stdout);int n;long long poz=1;long long res=1;scanf("%d",&n);for(int i=1;i<=2*n;i++)if(i<=n)res*=i,res%=MOD;else if(i>n+1)poz*=i;poz%=MOD;res=log_put(res,MOD-2);poz*=res;poz%=MOD;printf("%lld\n",poz);return 0; ^ user.cpp:3:81: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] int main(){freopen("dirichlet.in","r",stdin);freopen("dirichlet.out","w",stdout);int n;long long poz=1;long long res=1;scanf("%d",&n);for(int i=1;i<=2*n;i++)if(i<=n)res*=i,res%=MOD;else if(i>n+1)poz*=i;poz%=MOD;res=log_put(res,MOD-2);poz*=res;poz%=MOD;printf("%lld\n",poz);return 0; ^ user.cpp:3:134: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] int main(){freopen("dirichlet.in","r",stdin);freopen("dirichlet.out","w",stdout);int n;long long poz=1;long long res=1;scanf("%d",&n);for(int i=1;i<=2*n;i++)if(i<=n)res*=i,res%=MOD;else if(i>n+1)poz*=i;poz%=MOD;res=log_put(res,MOD-2);poz*=res;poz%=MOD;printf("%lld\n",poz);return 0; ^