1.
#include <iostream>
using namespace std;
int main()
{
int n, i, v[100], s = 0;
cin >> n;
for (i = 1; i <= n; i++)
{
cin >> v[i];
}
for (i = 1; i <= n; i++)
{
if (v[i] % 10 == 6)
{
s += v[i];
}
}
cout << s;
return 0;
}
2.
#include <iostream>
using namespace std;
int main()
{
int n, i, v[100], s = 1;
cin >> n;
for (i = 1; i <= n; i++)
{
cin >> v[i];
}
for (i = 1; i <= n; i++)
{
if (i % 2 != 0)
{
s *= v[i];
}
}
cout << s;
return 0;
}