Find the missing two interger in array

We all know how to find one missing interger in array, my question is how can we find the two missing interger in interger array:

public void Find2MissingNum()
{
int[] iTol = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
int[] iMis = { 1, 2, 4, 6, 7, 8, 9, 10 };
int x, y;
// try to find 3, 5
//sum iMis
int sMis =0 , sTol=0;
foreach (int i in iMis)
{
sMis += i;
}
// sum iTol
sTol = iTol.Length * (iTol.Length + 1) / 2;
// time total
int tMis = 1, tTol = 1;
foreach (int i in iMis)
{
tMis *= i;
}
foreach (int i in iTol)
{
tTol *= i;
}
int timeSmisStol = tTol / tMis;
int difTM = sTol - sMis;
for (int i = 0; i < difTM; i++)
{
if (i * (difTM - i) == timeSmisStol)
{
x = i;
y = difTM - i;
}
}



}