#!/usr/bin/env python 
import sys 
  
def search2(a,m): 
    low = 0 
    high = len(a) - 1 
    while(low <= high): 
        mid = (low + high)/2 
        midval = a[mid] 
      
        if midval < m: 
            low = mid + 1 
        elif midval > m: 
            high = mid - 1 
        else: 
            print mid 
            return mid 
    print -1 
    return -1 
  
if __name__ == "__main__": 
    a = [int(i) for i in list(sys.argv[1])] 
    m = int(sys.argv[2]) 
    search2(a,m)