604 B | 604 chars
import sys
from math import sqrt, pi, sin, factorial, ceil, floor
from datetime import datetime, timedelta
# sys.setrecursionlimit(10**7)
BLANK = " "
# inp = input
inp = lambda : sys.stdin.readline().rstrip()
mii = lambda x = BLANK : [*map(int,inp().split(x))]
mfi = lambda x = BLANK : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
p = print
def solve():
a, b, n = mii()
b_left = n - b
b_cnt = b_left // (b - a) + int(b_left % (b- a) > 0)
print(b_cnt * 2 + 1)
if __name__ == "__main__":
tc = 1
for t in range(1, tc+1):
ret = solve()