Buggy python submission (verdict: Runtime Error):
import sys
def ass(v):
    if not v:
        print(-1)
        sys.exit(0)

h, w, k = map(int, input().split())
grid = [[1 if v == '1' else 0 for v in input()] for _ in range(h)]


ass(h > 0 and w > 0 and k > 0)
for row in grid:
    ass(len(row) == w)


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        ass(len(counters) == len(local_counters))
        while i < h:
            if (1 << i) & state:
                hi = i
            # print(hi, i, j)
            # print(grid[i])
            ass(len(local_counters) > hi)
            ass(i < h and j < w)
            ass(len(grid) > i)
            ass(len(grid[i]) > j)
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        # ass(len(counters))
        # ass(k)
        if max(counters) > k:
            # ass(hasattr(local_counters, 'copy'))
            counters = local_counters.copy()
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)



Fixed submission:
import sys
def ass(v):
    if not v:
        print(-1)
        sys.exit(0)

h, w, k = map(int, input().split())
grid = [[1 if v == '1' else 0 for v in input()] for _ in range(h)]


ass(h > 0 and w > 0 and k > 0)
for row in grid:
    ass(len(row) == w)


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        ass(len(counters) == len(local_counters))
        while i < h:
            if (1 << i) & state:
                hi = i
            # print(hi, i, j)
            # print(grid[i])
            ass(len(local_counters) > hi)
            ass(i < h and j < w)
            ass(len(grid) > i)
            ass(len(grid[i]) > j)
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        # ass(len(counters))
        # ass(k)
        if max(counters) > k:
            counters = local_counters[:]
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)

Buggy python submission (verdict: Runtime Error):
import sys
h, w, k = map(int, input().split())
grid = [[1 if v == '1' else 0 for v in input()] for _ in range(h)]

ass(False)
def ass(v):
    if not v:
        print(-1)
        sys.exit(0)

ass(h > 0 and w > 0 and k > 0)
for row in grid:
    ass(len(row) == w)


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        ass(len(counters) == len(local_counters))
        while i < h:
            if (1 << i) & state:
                hi = i
            # print(hi, i, j)
            # print(grid[i])
            ass(len(local_counters) > hi)
            ass(i < h and j < w)
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        if max(counters) > k:
            counters = local_counters.copy()
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)



Fixed submission:
import sys
def ass(v):
    if not v:
        print(-1)
        sys.exit(0)

h, w, k = map(int, input().split())
grid = [[1 if v == '1' else 0 for v in input()] for _ in range(h)]


ass(h > 0 and w > 0 and k > 0)
for row in grid:
    ass(len(row) == w)


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        ass(len(counters) == len(local_counters))
        while i < h:
            if (1 << i) & state:
                hi = i
            # print(hi, i, j)
            # print(grid[i])
            ass(len(local_counters) > hi)
            ass(i < h and j < w)
            ass(len(grid) > i)
            ass(len(grid[i]) > j)
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        # ass(len(counters))
        # ass(k)
        if max(counters) > k:
            counters = local_counters[:]
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)

Buggy python submission (verdict: Runtime Error):
import sys
h, w, k = map(int, input().split())
grid = [[1 if v == '1' else 0 for v in input()] for _ in range(h)]


def ass(v):
    if not v:
        print(-1)
        sys.exit(0)

ass(h > 0 and w > 0 and k > 0)
for row in grid:
    ass(len(row) == w)


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        ass(len(counters) == len(local_counters))
        while i < h:
            if (1 << i) & state:
                hi = i
            # print(hi, i, j)
            # print(grid[i])
            ass(len(local_counters) > hi)
            ass(i < h and j < w)
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        if max(counters) > k:
            counters = local_counters.copy()
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)



Fixed submission:
import sys
def ass(v):
    if not v:
        print(-1)
        sys.exit(0)

h, w, k = map(int, input().split())
grid = [[1 if v == '1' else 0 for v in input()] for _ in range(h)]


ass(h > 0 and w > 0 and k > 0)
for row in grid:
    ass(len(row) == w)


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        ass(len(counters) == len(local_counters))
        while i < h:
            if (1 << i) & state:
                hi = i
            # print(hi, i, j)
            # print(grid[i])
            ass(len(local_counters) > hi)
            ass(i < h and j < w)
            ass(len(grid) > i)
            ass(len(grid[i]) > j)
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        # ass(len(counters))
        # ass(k)
        if max(counters) > k:
            counters = local_counters[:]
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)

Buggy python submission (verdict: Runtime Error):
import sys
h, w, k = map(int, input().split())
grid = [[int(v) for v in input()] for _ in range(h)]


def ass(v):
    if not v:
        print(-1)
        sys.exit(0)

ass(h > 0 and w > 0 and k > 0)
for row in grid:
    ass(len(row) == w)


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        while i < h:
            if (1 << i) & state:
                hi = i
            # print(hi, i, j)
            # print(grid[i])
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        if max(counters) > k:
            counters = local_counters.copy()
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)



Fixed submission:
import sys
def ass(v):
    if not v:
        print(-1)
        sys.exit(0)

h, w, k = map(int, input().split())
grid = [[1 if v == '1' else 0 for v in input()] for _ in range(h)]


ass(h > 0 and w > 0 and k > 0)
for row in grid:
    ass(len(row) == w)


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        ass(len(counters) == len(local_counters))
        while i < h:
            if (1 << i) & state:
                hi = i
            # print(hi, i, j)
            # print(grid[i])
            ass(len(local_counters) > hi)
            ass(i < h and j < w)
            ass(len(grid) > i)
            ass(len(grid[i]) > j)
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        # ass(len(counters))
        # ass(k)
        if max(counters) > k:
            counters = local_counters[:]
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)

Buggy python submission (verdict: Runtime Error):
import sys
h, w, k = map(int, input().split())
grid = [[int(v) for v in input()] for _ in range(h)]
if h == 0 or w == 0:
    print(-1)
    sys.exit(0)
for row in grid:
    if len(row) != w:
        print(-1)
        sys.exit(0)


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        while i < h:
            if (1 << i) & state:
                hi = i
            # print(hi, i, j)
            # print(grid[i])
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        if max(counters) > k:
            counters = local_counters.copy()
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)



Fixed submission:
import sys
def ass(v):
    if not v:
        print(-1)
        sys.exit(0)

h, w, k = map(int, input().split())
grid = [[1 if v == '1' else 0 for v in input()] for _ in range(h)]


ass(h > 0 and w > 0 and k > 0)
for row in grid:
    ass(len(row) == w)


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        ass(len(counters) == len(local_counters))
        while i < h:
            if (1 << i) & state:
                hi = i
            # print(hi, i, j)
            # print(grid[i])
            ass(len(local_counters) > hi)
            ass(i < h and j < w)
            ass(len(grid) > i)
            ass(len(grid[i]) > j)
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        # ass(len(counters))
        # ass(k)
        if max(counters) > k:
            counters = local_counters[:]
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)

Buggy python submission (verdict: Runtime Error):
h, w, k = map(int, input().split())
grid = [[int(v) for v in input()] for _ in range(h)]

print(grid)

def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        while i < h:
            if (1 << i) & state:
                hi = i
            # print(hi, i, j)
            # print(grid[i])
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        if max(counters) > k:
            counters = local_counters.copy()
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)



Fixed submission:
import sys
def ass(v):
    if not v:
        print(-1)
        sys.exit(0)

h, w, k = map(int, input().split())
grid = [[1 if v == '1' else 0 for v in input()] for _ in range(h)]


ass(h > 0 and w > 0 and k > 0)
for row in grid:
    ass(len(row) == w)


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        ass(len(counters) == len(local_counters))
        while i < h:
            if (1 << i) & state:
                hi = i
            # print(hi, i, j)
            # print(grid[i])
            ass(len(local_counters) > hi)
            ass(i < h and j < w)
            ass(len(grid) > i)
            ass(len(grid[i]) > j)
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        # ass(len(counters))
        # ass(k)
        if max(counters) > k:
            counters = local_counters[:]
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)

Buggy python submission (verdict: Runtime Error):
h, w, k = map(int, input().split())
grid = [[int(v) for v in input()] for _ in range(h)]


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        while i < h:
            if (1 << i) & state:
                hi = i + 1
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        if max(counters) > k:
            counters = local_counters.copy()
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)



Fixed submission:
import sys
def ass(v):
    if not v:
        print(-1)
        sys.exit(0)

h, w, k = map(int, input().split())
grid = [[1 if v == '1' else 0 for v in input()] for _ in range(h)]


ass(h > 0 and w > 0 and k > 0)
for row in grid:
    ass(len(row) == w)


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        ass(len(counters) == len(local_counters))
        while i < h:
            if (1 << i) & state:
                hi = i
            # print(hi, i, j)
            # print(grid[i])
            ass(len(local_counters) > hi)
            ass(i < h and j < w)
            ass(len(grid) > i)
            ass(len(grid[i]) > j)
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        # ass(len(counters))
        # ass(k)
        if max(counters) > k:
            counters = local_counters[:]
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)

Buggy python submission (verdict: Runtime Error):
h, w, k = map(int, input().split())
grid = [[int(v) for v in input()] for _ in range(h)]


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        while i < h:
            if (1 << i) & state:
                hi = i + 1
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        if max(counters) > k:
            counters = local_counters.copy()
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)



Fixed submission:
import sys
def ass(v):
    if not v:
        print(-1)
        sys.exit(0)

h, w, k = map(int, input().split())
grid = [[1 if v == '1' else 0 for v in input()] for _ in range(h)]


ass(h > 0 and w > 0 and k > 0)
for row in grid:
    ass(len(row) == w)


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        ass(len(counters) == len(local_counters))
        while i < h:
            if (1 << i) & state:
                hi = i
            # print(hi, i, j)
            # print(grid[i])
            ass(len(local_counters) > hi)
            ass(i < h and j < w)
            ass(len(grid) > i)
            ass(len(grid[i]) > j)
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        # ass(len(counters))
        # ass(k)
        if max(counters) > k:
            counters = local_counters[:]
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)

Buggy python submission (verdict: Runtime Error):
h, w, k = map(int, input().split())
grid = [[int(v) for v in input()] for _ in range(h)]


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << (h - 1)):
    j = 0
    vcnt = 0
    counters = [0] * h
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * h
        while i < h:
            if (1 << i) & state:
                hi = i + 1
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        if max(counters) > k:
            counters = local_counters.copy()
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)



Fixed submission:
import sys
def ass(v):
    if not v:
        print(-1)
        sys.exit(0)

h, w, k = map(int, input().split())
grid = [[1 if v == '1' else 0 for v in input()] for _ in range(h)]


ass(h > 0 and w > 0 and k > 0)
for row in grid:
    ass(len(row) == w)


def count_ones(i):
    cnt = 0
    while i:
        if i & 1:
            cnt += 1
        i >>= 1
    return cnt

ans = h + w

for state in range(1 << h):
    j = 0
    vcnt = 0
    counters = [0] * (h + 1)
    is_ok = True
    while j < w:
        hi = 0
        i = 0
        local_counters = [0] * (h + 1)
        ass(len(counters) == len(local_counters))
        while i < h:
            if (1 << i) & state:
                hi = i
            # print(hi, i, j)
            # print(grid[i])
            ass(len(local_counters) > hi)
            ass(i < h and j < w)
            ass(len(grid) > i)
            ass(len(grid[i]) > j)
            local_counters[hi] += grid[i][j]
            i += 1
        for i, v in enumerate(local_counters):
            if v > k:
                is_ok = False
                break
            counters[i] += local_counters[i]
        if not is_ok:
            break
        # ass(len(counters))
        # ass(k)
        if max(counters) > k:
            counters = local_counters[:]
            vcnt += 1

        j += 1


    if is_ok and ans > count_ones(state) + vcnt:
        ans = count_ones(state) + vcnt
print(ans)