Buggy python submission (verdict: Time Limit Exceeded):
n,m,l=map(int,raw_input().split())
INF=(10**9)+1

g=[]
f=[]
for i in xrange(n):
    g.append([INF]*(n))
    f.append([INF]*(n))

for i in xrange(len(g)):
    for j in xrange(len(g)):
        if i==j:
            g[i][j]=0
            f[i][j]=0

for i in xrange(m):
    a,b,c=map(int,raw_input().split())
    g[a-1][b-1]=c
    g[b-1][a-1]=c
    f[a-1][b-1]=c
    f[b-1][a-1]=c

for k in xrange(n):
    for i in xrange(n):
        for j in xrange(n):
            g[i][j]=min(g[i][j],g[i][k]+g[k][j])
            f[i][j]=min(f[i][j],f[i][k]+f[k][j])

for i in xrange(n):
    for j in xrange(n):
        if f[i][j]<=l:
            g[i][j]=1
        else:
            g[i][j]=INF
        if i==j:
            g[i][j]=0

for k in xrange(n):
    for i in xrange(n):
        for j in xrange(n):
            g[i][j]=min(g[i][j],g[i][k]+g[k][j])

q=int(raw_input())
for i in xrange(q):
    s,t=map(int,raw_input().split())
    u=g[s-1][t-1]

    if u>=INF:
        print (-1)
    else:
        print (u-1)

Fixed submission:
n,m,l=map(int,raw_input().split())
INF=(10**9)+1

g=[]
f=[]
for i in xrange(n):
    g.append([INF]*(n))
    f.append([INF]*(n))

for i in xrange(len(g)):
    for j in xrange(len(g)):
        if i==j:
            g[i][j]=0
            f[i][j]=0

for i in xrange(m):
    a,b,c=map(int,raw_input().split())
    g[a-1][b-1]=c
    g[b-1][a-1]=c
    f[a-1][b-1]=c
    f[b-1][a-1]=c

for k in xrange(n):
    for i in xrange(n):
        for j in xrange(n):
            g[i][j]=min(g[i][j],g[i][k]+g[k][j])
            f[i][j]=min(f[i][j],f[i][k]+f[k][j])

for i in xrange(n):
    for j in xrange(n):
        if f[i][j]<=l:
            g[i][j]=1
        else:
            g[i][j]=INF
        if i==j:
            g[i][j]=0

for k in xrange(n):
    for i in xrange(n):
        for j in xrange(n):
            g[i][j]=min(g[i][j],g[i][k]+g[k][j])

q=int(raw_input())
for i in xrange(q):
    s,t=map(int,raw_input().split())
    u=g[s-1][t-1]

    if u>=INF:
        print (-1)
    else:
        print (u-1)

Buggy python submission (verdict: Runtime Error):
import math

n,m,l=map(int,raw_raw_input().split())
INF=(10**9)+1

g=[]
f=[]
for i in xrange(n):
    g.append([INF]*(n))
    f.append([INF]*(n))

for i in xrange(len(g)):
    for j in xrange(len(g)):
        if i==j:
            g[i][j]=0
            f[i][j]=0

for i in xrange(m):
    a,b,c=map(int,raw_input().split())
    g[a-1][b-1]=c
    g[b-1][a-1]=c
    f[a-1][b-1]=c
    f[b-1][a-1]=c

for k in xrange(n):
    for i in xrange(n):
        for j in xrange(n):
            g[i][j]=min(g[i][j],g[i][k]+g[k][j])
            f[i][j]=min(f[i][j],f[i][k]+f[k][j])

for i in xrange(n):
    for j in xrange(n):
        if f[i][j]<=l:
            g[i][j]=1
        else:
            g[i][j]=INF
        if i==j:
            g[i][j]=0

for k in xrange(n):
    for i in xrange(n):
        for j in xrange(n):
            g[i][j]=min(g[i][j],g[i][k]+g[k][j])

q=int(raw_input())
for i in xrange(q):
    s,t=map(int,raw_input().split())
    u=g[s-1][t-1]

    if u>=INF:
        print (-1)
    else:
        print (u-1)

Fixed submission:
n,m,l=map(int,raw_input().split())
INF=(10**9)+1

g=[]
f=[]
for i in xrange(n):
    g.append([INF]*(n))
    f.append([INF]*(n))

for i in xrange(len(g)):
    for j in xrange(len(g)):
        if i==j:
            g[i][j]=0
            f[i][j]=0

for i in xrange(m):
    a,b,c=map(int,raw_input().split())
    g[a-1][b-1]=c
    g[b-1][a-1]=c
    f[a-1][b-1]=c
    f[b-1][a-1]=c

for k in xrange(n):
    for i in xrange(n):
        for j in xrange(n):
            g[i][j]=min(g[i][j],g[i][k]+g[k][j])
            f[i][j]=min(f[i][j],f[i][k]+f[k][j])

for i in xrange(n):
    for j in xrange(n):
        if f[i][j]<=l:
            g[i][j]=1
        else:
            g[i][j]=INF
        if i==j:
            g[i][j]=0

for k in xrange(n):
    for i in xrange(n):
        for j in xrange(n):
            g[i][j]=min(g[i][j],g[i][k]+g[k][j])

q=int(raw_input())
for i in xrange(q):
    s,t=map(int,raw_input().split())
    u=g[s-1][t-1]

    if u>=INF:
        print (-1)
    else:
        print (u-1)

Buggy python submission (verdict: Time Limit Exceeded):
import math

n,m,l=map(int,input().split())
INF=(10**9)+1

g=[]
f=[]
for i in range(n):
    g.append([INF]*(n))
    f.append([INF]*(n))

for i in range(len(g)):
    for j in range(len(g)):
        if i==j:
            g[i][j]=0
            f[i][j]=0

for i in range(m):
    a,b,c=map(int,input().split())
    g[a-1][b-1]=c
    g[b-1][a-1]=c
    f[a-1][b-1]=c
    f[b-1][a-1]=c

for k in range(n):
    for i in range(n):
        for j in range(n):
            g[i][j]=min(g[i][j],g[i][k]+g[k][j])
            f[i][j]=min(f[i][j],f[i][k]+f[k][j])

for i in range(n):
    for j in range(n):
        if f[i][j]<=l:
            g[i][j]=1
        else:
            g[i][j]=INF
        if i==j:
            g[i][j]=0

for k in range(n):
    for i in range(n):
        for j in range(n):
            g[i][j]=min(g[i][j],g[i][k]+g[k][j])

q=int(input())
for i in range(q):
    s,t=map(int,input().split())
    u=g[s-1][t-1]

    if u>=INF:
        print (-1)
    else:
        print (u-1)

Fixed submission:
n,m,l=map(int,raw_input().split())
INF=(10**9)+1

g=[]
f=[]
for i in xrange(n):
    g.append([INF]*(n))
    f.append([INF]*(n))

for i in xrange(len(g)):
    for j in xrange(len(g)):
        if i==j:
            g[i][j]=0
            f[i][j]=0

for i in xrange(m):
    a,b,c=map(int,raw_input().split())
    g[a-1][b-1]=c
    g[b-1][a-1]=c
    f[a-1][b-1]=c
    f[b-1][a-1]=c

for k in xrange(n):
    for i in xrange(n):
        for j in xrange(n):
            g[i][j]=min(g[i][j],g[i][k]+g[k][j])
            f[i][j]=min(f[i][j],f[i][k]+f[k][j])

for i in xrange(n):
    for j in xrange(n):
        if f[i][j]<=l:
            g[i][j]=1
        else:
            g[i][j]=INF
        if i==j:
            g[i][j]=0

for k in xrange(n):
    for i in xrange(n):
        for j in xrange(n):
            g[i][j]=min(g[i][j],g[i][k]+g[k][j])

q=int(raw_input())
for i in xrange(q):
    s,t=map(int,raw_input().split())
    u=g[s-1][t-1]

    if u>=INF:
        print (-1)
    else:
        print (u-1)

Buggy python submission (verdict: Time Limit Exceeded):
import math

n,m,l=map(int,input().split())
INF=(10**9)+1

g=[]
f=[]
for i in range(n):
    g.append([INF]*(n))
    f.append([INF]*(n))

for i in range(len(g)):
    for j in range(len(g)):
        if i==j:
            g[i][j]=0
            f[i][j]=0

for i in range(m):
    a,b,c=map(int,input().split())
    g[a-1][b-1]=c
    g[b-1][a-1]=c
    f[a-1][b-1]=c
    f[b-1][a-1]=c

for k in range(n):
    for i in range(n):
        for j in range(n):
            g[i][j]=min(g[i][j],g[i][k]+g[k][j])
            f[i][j]=min(f[i][j],f[i][k]+f[k][j])

for i in range(n):
    for j in range(n):
        if f[i][j]<=l:
            g[i][j]=1
        else:
            g[i][j]=INF
        if i==j:
            g[i][j]=0

for k in range(n):
    for i in range(n):
        for j in range(n):
            g[i][j]=min(g[i][j],g[i][k]+g[k][j])

q=int(input())
for i in range(q):
    s,t=map(int,input().split())
    u=g[s-1][t-1]

    if u>=INF:
        print (-1)
    else:
        print (u-1)

Fixed submission:
n,m,l=map(int,raw_input().split())
INF=(10**9)+1

g=[]
f=[]
for i in xrange(n):
    g.append([INF]*(n))
    f.append([INF]*(n))

for i in xrange(len(g)):
    for j in xrange(len(g)):
        if i==j:
            g[i][j]=0
            f[i][j]=0

for i in xrange(m):
    a,b,c=map(int,raw_input().split())
    g[a-1][b-1]=c
    g[b-1][a-1]=c
    f[a-1][b-1]=c
    f[b-1][a-1]=c

for k in xrange(n):
    for i in xrange(n):
        for j in xrange(n):
            g[i][j]=min(g[i][j],g[i][k]+g[k][j])
            f[i][j]=min(f[i][j],f[i][k]+f[k][j])

for i in xrange(n):
    for j in xrange(n):
        if f[i][j]<=l:
            g[i][j]=1
        else:
            g[i][j]=INF
        if i==j:
            g[i][j]=0

for k in xrange(n):
    for i in xrange(n):
        for j in xrange(n):
            g[i][j]=min(g[i][j],g[i][k]+g[k][j])

q=int(raw_input())
for i in xrange(q):
    s,t=map(int,raw_input().split())
    u=g[s-1][t-1]

    if u>=INF:
        print (-1)
    else:
        print (u-1)