def getSecondMostFreq(str) :
 
    NO_OF_CHARS = 256
 
   
    count = [0] * NO_OF_CHARS
 
  
    for i in range(len(str)) :
        count[ord(str[i])] += 1
 
    first, second = 0, 0
 
  
    for i in range(NO_OF_CHARS) :
 
        
        if count[i] > count[first] :
 
            second = first
            first = i
 
       
        elif (count[i] > count[second] and
            count[i] != count[first] ) :
             
            second = i
 

    return chr(second)
 

if __name__ == "__main__" :
 
    str = "aabababa"

    res = getSecondMostFreq(str)
    if res != '\0' :
        print("Second most frequent char is", res)
    else :
        print("No second most frequent character")