import Foundation
var s = String(readLine()!)
let t = String(readLine()!)
var c = 0
if t.count == 1 && s.contains(t){
    print(-1)
}else{
    let i = t.startIndex
    let p = t[...i] + "." + t[t.index(after: i)...]
    let q = s.replacingOccurrences(of: t, with: p)
    print(q.count - s.count)
}