((input) => {
    const lines = input.split("\n");
    const [A, B] = lines[0].split(" ").map(x => x | 0);
    const S = lines[1];

    const cond = S.split("").find((e, idx) => idx === A ? e !== "-": e === "-") === null;
    console.log(cond ? "Yes" : "No");
})(require("fs").readFileSync("/dev/stdin", "utf8"));
//})(``);