#include<iostream> #include<cstdio> #include<cmath> #include<cstring> #include<ctime> #include<algorithm> using namespace std; #define lint __int64 lint Euler ( lint n ) { lint i, ret = n; for ( i = 2; i * i <= n; i++ ) { if ( n % i == 0 ) { n /= i; ret = ret - ret / i; while ( n % i == 0 ) n = n / i; } } if ( n > 1 ) ret = ret - ret / n; return ret; } int main() { lint n; while ( scanf("%I64d",&n) && n ) printf("%I64d\n",Euler(n)); return 0; }