# Alternating Sums

Several people are standing in a row and need to be divided into two teams. The first person goes into *team 1*, the second goes into *team 2*, the third goes into *team 1* again, the fourth into *team 2*, and so on.

You are given an array of positive integers - the weights of the people. Return an array of two integers, where the first element is the total weight of *team 1*, and the second element is the total weight of *team 2* after the division is complete.

## Example

For `a = [50, 60, 60, 45, 70]`

, the output should be

`alternating_sums(a) = [180, 105]`

## Solution

py

```
def alternating_sums(a):
return [sum(a[::2]), sum(a[1::2])]
print(alternating_sums([50, 60, 60, 45, 70]))
```

js

```
function alternatingSums(a) {
let sum1 = 0;
let sum2 = 0;
for (let i = 0; i < a.length; i++) {
if (i % 2 == 0) {
sum1 += a[i];
} else {
sum2 += a[i];
}
}
return [sum1, sum2];
}
console.log(alternatingSums([50, 60, 60, 45, 70]));
```