demo

gistfile1.txt

function demo ( A ) {
var count = A.length,
counter = [0,0],
equis = []; 
while(count--){
counter[1] += A[count]; 
}
count = A.length;
while(count--) {
counter[0] += A[count];
if (counter[0] == counter[1]) {
equis.push(count);
}
counter[1] -= A[count];
}
var int =  (equis.length)?equis:-1;
for(i = 0; i<int.length; i++) {
    return int[i];
    }
}