#include<stdio.h>
#include<string.h>

int main()
{
    int A,B,i,length;
    char s[2000];

    scanf("%d%d",&A,&B);
    scanf("%s",s);

    length=strlen(s);

    for(i=0;i<length;i++){
        if(s[A]!='-'){
            printf("No");
            break;
        }
        if(i==A){
            i++;
        }
        if(s[A]=='-'&&s[i]>=48&&s[i]<=57){
            if(i==(length-1)){
                printf("Yes");
                break;
            }
            else{
                continue;
            }
        }
        if(s[i]=='-'&&s[A]=='-'){
            printf("No");
            break;
        }
    }

    return 0;
}
