a,b = input().split(" ")
c = list(map(str,input().split()))
print(c[0][:int(b)-1] + c[0][int(b)-1].lower() + c[0][int(b):]) a,b = input().split(" ") a input().split(" ") ().split () input split " " b c = list(map(str,input().split())) c list(map(str,input().split())) list map(str,input().split()) map str input().split() ().split () input split print(c[0][:int(b)-1] + c[0][int(b)-1].lower() + c[0][int(b):]) print c[0][:int(b)-1] + c[0][int(b)-1].lower() + c[0][int(b):] c[0][:int(b)-1] + c[0][int(b)-1].lower() c[0][:int(b)-1] [0] c 0 :int(b)-1 int(b)-1 int(b) int b 1 c[0][int(b)-1].lower() [int(b)-1].lower [int(b)-1] [0] c 0 int(b)-1 int(b) int b 1 lower c[0][int(b):] [0] c 0 int(b): int(b) int b c = list(map(str,input().split())) list(map(str,input().split())) c b = input().split(" ") input().split(" ") b a,b = input().split(" ") input().split(" ") a
a,b = input().split(" ")
c = list(map(str,input().split()))
print(c[0][:int(b)-1] + c[0][int(b)-1].lower() + c[0][int(b):])