var mass=[1,2,5,9,8,6,5,4,3,3,2,1]
var mass2=[]
for(i=0;i<mass.length;i++)
for (m=1; m<mass.length;m++) {
if (mass[i] !== mass [m]) {
mass2.push(mass[i]);
}
else {break }
}
}
alert(mass2)
var mass2=[]
for(i=0;i<mass.length;i++)
for (m=1; m<mass.length;m++) {
if (mass[i] !== mass [m]) {
mass2.push(mass[i]);
}
else {break }
}
}
alert(mass2)