Get rid off negative averages

So I pulled this from the C++ tutorial here and played around with it to make it into a program that averages ten grades. How ever when I input all negative grades it gives a negative average. How would I and where would I input an if statement(not sure if this is what I would use) that would say basically if the average is less than zero than display ---%.

Thanks for your help I'm pretty new at all of this.

Code:

`int main()`

{

int grade[10];

int i,sum=0, avg=0;

int max=0,min=100;

for(i=0;i<10;i++)

{

cout << "Grade " << i+1 << ": ";

cin >> grade[i];

}

for(i=0;i<10;i++)

{

sum=sum+grade[i];

if(grade[i]>max)

{

max=grade[i];

}

if(grade[i]<min)

{

min=grade[i];

}

}

avg=sum/10;

cout << "Average Grade: " << avg << "%" << endl;

return 0;

}