小马智行第2ac, 第3动规30%，思路估计错了。贴上第二题
"""
青蛙跳：只能跳下一个或者跳与自己最近的相同颜色的台阶，c是台阶颜色
"""
n = int(input())
c = [int(i) for i in input().split()]
def getMinSteps(n, c):
dic_c = {}
if n<=2:
return n-1
dp = [n]*n
dp[0],dp[1] = 0, 1
dic_c[c[0]] = 0
dic_c[c[1]] = 1
for i in range(2, n):
if c[i] in dic_c:
dp[i] = min(dp[ dic_c[ c[i] ] ]+1, dp[i-1]+1)
else:
dp[i] = dp[i-1]+1
dic_c[ c[i] ] = i
return dp[-1]
print(getMinSteps(n, c))
