#include<iostream> #include<string> using namespace std; int main() { string str; char ch; int num = 0; cin >> ch >> str; int a = str.length(); for (int i = 0; i < a; i++) { if (ch == str[i] || toupper(ch) == str[i]) { num++; } } printf("%.5f\n", (float)num / a); }