N,K=map(int,input().split())
K-=1
S=input()
S=S[:K]+S[K].lower()+S[K+1:]
print(S) N,K=map(int,input().split()) N map(int,input().split()) map int input().split() ().split () input split K K-=1 K 1 S=input() S input() input S=S[:K]+S[K].lower()+S[K+1:] S S[:K]+S[K].lower()+S[K+1:] S[:K]+S[K].lower() S[:K] S :K K S[K].lower() [K].lower [K] S K lower S[K+1:] S K+1: K+1 K 1 print(S) print S S=input() input() S S=S[:K]+S[K].lower()+S[K+1:] S[:K]+S[K].lower()+S[K+1:] S K=map(int,input().split()) map(int,input().split()) K N,K=map(int,input().split()) map(int,input().split()) N K-=1 1 K
N,K=map(int,input().split())
K-=1
S=input()
S=S[:K]+S[K].lower()+S[K+1:]
print(S)