Can anyone explaine why it counts twice?

here is my code

```
function mutation(arr) {
let z = arr[0].split("")
let x = arr[1].split("")
for (let i = 0; i<z.length; i++){
z[i] = z[i].toLowerCase()
}
for (let i = 0; i<x.length; i++){
x[i] = x[i].toLowerCase()
}
let c = 0;
for (let i = 0; i<z.length; i++){
for (let k = 0; k<x.length; k++){
if (z[i] == x[k]){
c++
console.log(c, z[i], x[k])
}
}
}
if (c == x.length){
return true
} else {
return false
}
}
console.log(mutation(["floor", "for"]));
```