A, B, T = map(int,raw_input().split())
over = min((A-T%A)%A, (B-T%B)%B)
for i in xrange(1,100000):
    if T >= i*A:
        over = min(over, (B-(T%A+i*A)%B)%B)
    if T >= i*B:
        over = min(over, (A-(T%B+i*B)%A)%A)
print T+over