X=input()
X=X.split()
str=input()
ans=int(X[1])-1
exact=str[ans].lower()
before=str[0:ans]
after=str[ans+1:]
print(before+exact+after) X=input() X input() input X=X.split() X X.split() X.split X split str=input() str input() input ans=int(X[1])-1 ans int(X[1])-1 int(X[1]) int X[1] X 1 1 exact=str[ans].lower() exact str[ans].lower() [ans].lower [ans] str ans lower before=str[0:ans] before str[0:ans] str 0:ans 0 ans after=str[ans+1:] after str[ans+1:] str ans+1: ans+1 ans 1 print(before+exact+after) print before+exact+after before+exact before exact after X=input() input() X X=X.split() X.split() X after=str[ans+1:] str[ans+1:] after str=input() input() str exact=str[ans].lower() str[ans].lower() exact before=str[0:ans] str[0:ans] before ans=int(X[1])-1 int(X[1])-1 ans
X=input()
X=X.split()
str=input()
ans=int(X[1])-1
exact=str[ans].lower()
before=str[0:ans]
after=str[ans+1:]
print(before+exact+after)