A, B, T = map(int,raw_input().split())
over = min((A-T%A)%A, (B-T%B)%B)
for i in xrange(1,10000000):
    if T >= i*A:
        x = B-(T%A+i*A)%B
        over = min(over, x%A, x%B)
    if T >= i*B:
        x = A-(T%A+i*B)%A
        over = min(over, x%A, x%B)
print T+over