P5131

def suan(x1,y1,x2,y2):
    return ((x2-x1)**2+(y2-y1)**2)**0.5
a=list(map(float,input().split(',')))
l=len(a)
ans=suan(0,0,a[0],a[1])
for i in range(2,l,2):
    ans+=suan(a[i-2],a[i-1],a[i],a[i+1])
print("折线长度为："+str(ans))

P5107

a=list(map(int,input().split(',')))
l=len(a)
ans=[]
i=0
while(i<l):
    if a[i]: 
        ans.append(a[i])
        i+=1
    elif a[i]==0:
        if a[i+1]==0:
            ans.append(0)
            i+=2
        else:
            for j in range(a[i+1]):
                ans.append(a[i+2])
            i+=3
l=len(ans)
for i in range(l-1):
    print(ans[i],end=',')
print(ans[l-1])

P5111

a=list(map(int,input().split()))
b=int(input())-1
n=len(a)
s=str(b+1)
for i in range(n-1):
    for j in range(n-1,0,-1):
        if(a[j]<a[j-1]):
            a[j],a[j-1]=a[j-1],a[j]
            if j==b:
                s+='→'+str(b)
                b-=1
            elif j-1==b:
                s+='→'+str(b+2)
                b+=1
for i in a:
    print(i,end=' ')
print()
print(s)