Buggy python submission (verdict: Runtime Error):
import sys
s = sys.stdin.readline().strip()
c_find = Fasle
f_find = False
for c in s:
    if c_find:
        if c == 'F':
            print 'Yes'
            exit(0)
    else:
        if c == 'C':
            c_find = True
print 'No'

Fixed submission:
import sys 
s = sys.stdin.readline().strip()
c_find = False                                                                                                                                                                                                                        
f_find = False
for c in s:
    if c_find:
        if c == 'F':
            print 'Yes'
            exit(0)
    else:
        if c == 'C':
            c_find = True
print 'No'

Buggy python submission (verdict: Runtime Error):
import sys
def range_union(al,ah,bl,bh):
    cl = max(al,bl)
    ch = min(ah,bh)
    if cl > ch:
        return 0
    else:
        return ch-cl +1

N = int(sys.stdin.readline())
T = map(int,sys.stdin.readline().strip().split())
A = map(int,sys.stdin.readline().strip().split())

p = 1
for i in xrange(1,N-1):
    if T[i-1] < T[i]:
        Tl = T[i]
        Th = T[i]
    elif T[i-1] == T[i]:
        Tl = 1
        Th = T[i]
    else:
        p = 0
        break

    if A[i] > A[i+1]:
        Al = A[i]
        Ah = A[i]
    elif A[i+1] == A[i]:
        Al = 1
        Ah = A[i]
    else:
        p = 0
        break

    r = range_union(Tl,Th,Al,Ah)
    if not r:
        p = 0
        break
    else:
        p = p*r


print p % 1000000007

Fixed submission:
import sys 
s = sys.stdin.readline().strip()
c_find = False                                                                                                                                                                                                                        
f_find = False
for c in s:
    if c_find:
        if c == 'F':
            print 'Yes'
            exit(0)
    else:
        if c == 'C':
            c_find = True
print 'No'

Buggy python submission (verdict: Runtime Error):
import sys
def range_union(al,ah,bl,bh):
    cl = max(al,bl)
    ch = min(ah,bh)
    if cl > ch:
        return 0
    else:
        return ch-cl +1

N = int(sys.stdin.readline())
T = map(int,sys.stdin.readline().strip().split())
A = map(int,sys.stdin.readline().strip().split())

p = 1
for i in xrange(1,N-1):
    if T[i-1] < T[i]:
        Tl = T[i]
        Th = T[i]
    elif T[i-1] == T[i]:
        Tl = 1
        Th = T[i]
    else:
        p = 0
        break

    if A[i] > A[i+1]:
        Al = A[i]
        Ah = A[i]
    elif A[i+1] == A[i]:
        Al = 1
        Ah = A[i]
    else:
        p = 0
        break

    r = range_union(Tl,Th,Al,Ah)
    if not r:
        p = 0
        break
    else:
        p = p*r


print p % 1000000007 

Fixed submission:
import sys 
s = sys.stdin.readline().strip()
c_find = False                                                                                                                                                                                                                        
f_find = False
for c in s:
    if c_find:
        if c == 'F':
            print 'Yes'
            exit(0)
    else:
        if c == 'C':
            c_find = True
print 'No'