#include <stdio.h>
int a,b;
char s[11];
int main(){
scanf("%d%d",&a,&b);
scanf("%c",&s);
for(int k=0;k<a;k++){
if(0<=(int)s[k]&&(int)s[k]<=9){}else{printf("No");return 0;}
}
for(int k=a;k<a+b+1;k++){
if(0<=(int)s[k]&&(int)s[k]<=9){}else{printf("No");return 0;}
}
if(s[a]!="-"){printf("No");return 0;}
printf("Yes");
return 0;
}