105. Div 3
time limit per test: 0.25
sec. There is sequence 1, 12, 123, 1234, ..., 12345678910, ... . Given first N elements of that sequence. You must determine amount of numbers in it that are divisible by 3. Input Input contains N (1<=N<=2^{31} - 1). Output Write answer to the output. Sample Input 4 Sample Output 2 |