#include <stdio.h>


int main(){
	int A, B, post = 0;
	char S[20];
	
	scanf("%d %d %s", &A, &B, S);
	
	for(int i = 0; S[i] != '\0'; i++) {
		(S[i] == '-')? post += i + 1 : post += 0;
	}
	post == A+1 ? puts("Yes") : puts("No");
	
	return 0;
}