D. Tanya and Password time limit per test2 seconds memory limit per test256 megabytes inputstandard input outputstandard output While dad was at work, a little girl Tanya decided to play with dad

题目：http://acm.hust.edu.cn/vjudge/problem/viewProblem.action?id=111980 Tanya and Password Time Limit: 2000MS Memory Limit: 262144KB 64bit IO Format: %I64d & %I64u Submit Status Descript

题目描述 Little girl Tanya climbs the stairs inside a multi-storey building. Every time Tanya climbs a stairway, she starts counting steps from 1 1 1 to the number of steps in this stairway. She speak