Buggy python submission (verdict: Runtime Error):
S = input()
K = int(input())
L = len(S)
a = S[0]
i = 0
C = []
while i < L-1:
    count = 1
    b,c = S[i],S[i+1]
    i+= 1
    while b == c:
        count += 1
        if i == L-1:
            break
        b,c = S[i],S[i+1]
        i += 1
    C.append(count)
if a != S[L-1]:
    num = 0
    for co in C:
        num += co//2
    print(int(num*K))
else:
    num1 = 0
    for co in C:
        num1 += co//2
    num2 = (C[len(C)-1]+1)//2
    for co in C[:len(C)-1]:
        num2 += co//2
    print(int(num1+num2*(K-1)))

Fixed submission:
S = input()
K = int(input())
L = len(S)
a = S[0]
i = 0
C = []
if L == 1:
    C = [1]
while i < L-1:
    count = 1
    b,c = S[i],S[i+1]
    i+= 1
    while b == c:
        count += 1
        if i == L-1:
            break
        b,c = S[i],S[i+1]
        i += 1
    C.append(count)
if a != S[L-1]:
    num = 0
    for co in C:
        num += co//2
    ans = int(num*K)
else:
    if len(C) == 1:
        ans  = L*K//2
    else:
        num1 = 0
        for co in C:
            num1 += co//2
        num2 = (C[len(C)-1]+C[0])//2
        for co in C[1:len(C)-1]:
            num2 += co//2
        ans = int(num1+num2*(K-1))
print(ans)

Buggy python submission (verdict: Runtime Error):
S = input()
K = int(input())
L = len(S)
a = S[0]
i = 0
C = []
while i < L-1:
    count = 1
    b,c = S[i],S[i+1]
    i+= 1
    while b == c:
        count += 1
        if i == L-1:
            C.append(count)
            break
        b,c = S[i],S[i+1]
        i += 1
    if i == L-1:
        break
    C.append(count)
if a != S[L-1]:
    num = 0
    for co in C:
        num += co//2
    print(int(num*K))
else:
    num1 = 0
    for co in C:
        num1 += co//2
    num2 = (C[len(C)-1]+1)//2
    for co in C[:len(C)-1]:
        num2 += co//2
    print(int(num1+num2*(K-1)))

Fixed submission:
S = input()
K = int(input())
L = len(S)
a = S[0]
i = 0
C = []
if L == 1:
    C = [1]
while i < L-1:
    count = 1
    b,c = S[i],S[i+1]
    i+= 1
    while b == c:
        count += 1
        if i == L-1:
            break
        b,c = S[i],S[i+1]
        i += 1
    C.append(count)
if a != S[L-1]:
    num = 0
    for co in C:
        num += co//2
    ans = int(num*K)
else:
    if len(C) == 1:
        ans  = L*K//2
    else:
        num1 = 0
        for co in C:
            num1 += co//2
        num2 = (C[len(C)-1]+C[0])//2
        for co in C[1:len(C)-1]:
            num2 += co//2
        ans = int(num1+num2*(K-1))
print(ans)

Buggy python submission (verdict: Runtime Error):
S = input()
K = int(input())
L = len(S)
a = S[0]
modi = 0
i = 0
C = []
while i < L-1:
    count = 1
    b,c = S[i],S[i+1]
    i+= 1
    while b == c:
        count += 1
        if i == L-1:
            C.append(count)
            break
        b,c = S[i],S[i+1]
        i += 1
    if i == L-1:
        break
    C.append(count)
if a != S[L-1]:
    num = 0
    for co in C:
        num += co//2
    print(int(num*K))
else:
    num1 = 0
    for co in C:
        num1 += co//2
    num2 = (C[len(C)-1]+1)//2
    for co in C[:len(C)-1]:
        num2 += co//2
        print(co,co//2)
    print(int(num1+num2*(K-1)))

Fixed submission:
S = input()
K = int(input())
L = len(S)
a = S[0]
i = 0
C = []
if L == 1:
    C = [1]
while i < L-1:
    count = 1
    b,c = S[i],S[i+1]
    i+= 1
    while b == c:
        count += 1
        if i == L-1:
            break
        b,c = S[i],S[i+1]
        i += 1
    C.append(count)
if a != S[L-1]:
    num = 0
    for co in C:
        num += co//2
    ans = int(num*K)
else:
    if len(C) == 1:
        ans  = L*K//2
    else:
        num1 = 0
        for co in C:
            num1 += co//2
        num2 = (C[len(C)-1]+C[0])//2
        for co in C[1:len(C)-1]:
            num2 += co//2
        ans = int(num1+num2*(K-1))
print(ans)