COROANA TE ROG!!!
1
#include<iostream>
using namespace std;
int main(){
int n;
cin>>n;
cout<<(n*(n+1))/2; //suma lui gauss
return 0;
}
2
#include<iostream>
using namespace std;
int main(){
int n, p=1;
cin>>n;
do{
p*=(n%10);
n/=10;
}while(n!=0);
cout<<p;
return 0;
}