#include <iostream>
int main(){
  int a,b,r=1;
  char c[12]={};
  std::cin>>a>>b>>c;
  for(int i=0;i<a+b+1;++i){
    if(i==a){r=(c[i]=='-'?r:0);}
    else{r=(c[i]>47&&c[i]<58?r:0);}
  }
  std::cout<<(r?"Yes":"No")<<"\n";
}