#include #define FOR(i, l, r) for(int i = (l) ; i < (r); i++) #define REV(i, l, r) for(int i = (r) - 1; i >= (l); i--) #define INC(i, n) FOR(i, 0, n) #define DEC(i, n) REV(i, 0, n) #define INC1(i, n) FOR(i, 1, (n) + 1) #define DEC1(i, n) REV(i, 1, (n) + 1) typedef long long signed int LL; typedef long long unsigned int LU; int n; int main() { scanf("%d", &n); int a = 1, ans = 0; while(a < n) { a *= 2; ans++; } printf("%d\n", ans); return 0; }