Buggy python submission (verdict: Runtime Error):
N, M = map(int, input().split())
a = [0]*N
for i in range(M):
    s, c = map(int, input().split())
    d = a[s-1]
    if s == 1 and c == 0:
        print("-1")
        break
    if d != 0:
        a[s-1] = min(c, d)
    else:
        a[s-1] = c
if M == 0:
    if N == 1:
        print(0)
    elif N == 2:
        print(10)
    else:
        print(100)
else:
    if a[0] == 0:
        a[1] = 1
        print(*a, sep="") 
    else:
        print(*a, sep="") 

Fixed submission:
N, M = map(int, input().split())
A=[]
for j in range(M):
    s, c = map(int, input().split())
    A.append([s-1, str(c)])
if N == 1:
    b = 0
elif N == 2:
    b= 10
else:
    b = 100
ans=[]
for i in range(b, 1000):
    a = 0
    for j in range(M):
        x=str(i)
        if len(x) < N:
            break 
        if A[j][1] == x[A[j][0]]:
            a += 1
    if a == M:
        ans.append(i)
if ans == []:
    print(-1)
else:
    print(min(ans))

Buggy python submission (verdict: Runtime Error):
N, M = map(int, input().split())
a = [0]*N
for i in range(M):
    s, c = map(int, input().split())
    d = a[s-1]
    if s == 1 and c == 0:
        print("-1")
        break
    if d != 0:
        a[s-1] = min(c, d)
    else:
        a[s-1] = c
if M == 0:
    if N == 1:
        print(0)
    elif N == 2:
        print(10)
    else:
        print(100)
else:
    if a[0] == 0:
        a[1] == 1
        print(*a, sep="") 
    else:
        print(*a, sep="") 

Fixed submission:
N, M = map(int, input().split())
A=[]
for j in range(M):
    s, c = map(int, input().split())
    A.append([s-1, str(c)])
if N == 1:
    b = 0
elif N == 2:
    b= 10
else:
    b = 100
ans=[]
for i in range(b, 1000):
    a = 0
    for j in range(M):
        x=str(i)
        if len(x) < N:
            break 
        if A[j][1] == x[A[j][0]]:
            a += 1
    if a == M:
        ans.append(i)
if ans == []:
    print(-1)
else:
    print(min(ans))

Buggy python submission (verdict: Runtime Error):
N, M = map(int, input().split())
a = [0]*N
for i in range(M):
    s, c = map(int, input().split())
    if a[s-1] =! 0:
        a[s-1] = min(c, a[s-1])
if M == 0:
    if N == 1:
        print(0)
    elif N == 2:
        print(10)
    else:
        print(100)
else:
    if a[0] != 0:
        print(*a, sep="") 
    else:
        print("-1")

Fixed submission:
N, M = map(int, input().split())
A=[]
for j in range(M):
    s, c = map(int, input().split())
    A.append([s-1, str(c)])
if N == 1:
    b = 0
elif N == 2:
    b= 10
else:
    b = 100
ans=[]
for i in range(b, 1000):
    a = 0
    for j in range(M):
        x=str(i)
        if len(x) < N:
            break 
        if A[j][1] == x[A[j][0]]:
            a += 1
    if a == M:
        ans.append(i)
if ans == []:
    print(-1)
else:
    print(min(ans))

Buggy python submission (verdict: Runtime Error):
N, M = map(int, input().split())
a = [0]*M
for i in range(M):
    s, c = map(int, input().split())
    a[s-1] = c
if a[0] == 0:
    print("-1")
else:
    print(*a, sep="") 

Fixed submission:
N, M = map(int, input().split())
A=[]
for j in range(M):
    s, c = map(int, input().split())
    A.append([s-1, str(c)])
if N == 1:
    b = 0
elif N == 2:
    b= 10
else:
    b = 100
ans=[]
for i in range(b, 1000):
    a = 0
    for j in range(M):
        x=str(i)
        if len(x) < N:
            break 
        if A[j][1] == x[A[j][0]]:
            a += 1
    if a == M:
        ans.append(i)
if ans == []:
    print(-1)
else:
    print(min(ans))

Buggy python submission (verdict: Runtime Error):
N, M = map(int, input().split())
a = [0]*M
for i in range(M):
    s, c = map(int, input().split())
    a[s-1] = c
if a[0] == 0:
    print("-1")
else:
    print(*a, sep="")    

Fixed submission:
N, M = map(int, input().split())
A=[]
for j in range(M):
    s, c = map(int, input().split())
    A.append([s-1, str(c)])
if N == 1:
    b = 0
elif N == 2:
    b= 10
else:
    b = 100
ans=[]
for i in range(b, 1000):
    a = 0
    for j in range(M):
        x=str(i)
        if len(x) < N:
            break 
        if A[j][1] == x[A[j][0]]:
            a += 1
    if a == M:
        ans.append(i)
if ans == []:
    print(-1)
else:
    print(min(ans))