#incclude<stdio.h>

int main(){
	int a,b,i;
	char s[];
	scanf("%d%d"&a,&b);
	scanf("%s",s);
	for(i=0;i<a;i++){
		if(s[i]!='0' || s[i]!='1' || s[i]!='2' || s[i]!='3' || s[i]!='4' || s[i]!='5' || s[i]!='6' || s[i]!='7' || s[i]!='8' || s[i]!='9'){
			printf("No/n");
			return 0;
		}
	}
	if(s[i]!='-'){
		printf("No/n");
			return 0;
	}
	for(i=1;i<=b;i++){
		if(s[a+i]!='0' || s[a+i]!='1' || s[a+i]!='2' || s[a+i]!='3' || s[a+i]!='4' || s[a+i]!='5' || s[a+i]!='6' || s[a+i]!='7' || s[a+i]!='8' || s[a+i]!='9'){
			printf("No/n");
			return 0;
		}
	}
	if(s[a+b+1]!='\0'){
		printf("No/n");
			return 0;
	}
	printf("Yes\n");
	return 0;
}