#include <iostream> #include <string> using namespace std; int main(){ int n; cin >> n; string str; cin >> str; long long cnt = 0, x = 1; for(int i = 0 ; i < n ; ++ i){ if(str[i] == 'B') cnt+=(x << i); } cout<<cnt<<endl; }
Codeforces Round #233 (Div. 2) |
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