can someone explain!

====================================================== ========================= 20. What's the output of the following code? void sum(int n, int n, int &s) nl = nl * nl; n2 = n2 * n2; s = n1 + n2; int main( void ) { int nl = 10, n2 = 11; int total = 0; sum ( ni, n2, total ); cout nl