K-th digit of number

package main
import "fmt"
import "math"

func main() {
        var a, i, k, temp int64
    fmt.Scanf("%d", &k)

    for ; k >= a; i++ {
        temp = a
        a+=  (int64)(9*math.Pow(10, float64(i))*float64(i+1))
    }

    c := i - 1
    d := (k - temp) / i
    temp2 := (int64)(math.Pow(10, float64(c)) + float64(d))
    k = i - (k-temp)%i

    for ;k >= 2; k-- { temp2 /= 10 }
    fmt.Printf("%d", temp2%10)
}