function gcd(a, b) {
while (a !== b) {
if (a > b) {
a = a - b;
} else {
b = b - a;
}
}
return a;
}
console.log(gcd(80, 180))
console.log(gcd(80, 100))
console.log(gcd(80, 20))
console.log(gcd(40, 20))
console.log(gcd(20, 20))
// poniższe trzy przypadki nie zadziałają!
// console.log(gcd(20, 0))
// console.log(gcd(-80, -180))
// console.log(gcd(-80, 180))
console.log(gcd(23434, 3256))
console.log(gcd(2137, 131))
console.log(gcd(42, 56))
console.log(gcd(348, 192))