#include using namespace std; using LL=long long; using ULL=unsigned long long; #define rep(i,n) for(int i=0; i<(n); i++) int N; LL X; LL A[200000]; int main(){ scanf("%d%lld",&N,&X); rep(i,N) scanf("%lld",&A[i]); LL v=-X*(N-1); rep(i,N) v+=A[i]; printf("%lld\n",v); return 0; }