'use strict'

function main(input) {


    input = input.split(/\n|\s/)//.map(v => ~~v)
    const a = ~~input[0]
    const b = ~~input[1]
    const s = input[2]

    let ans = 'No'
    if (s.slice(0, a).match(/^[0-9]+$/) &&
        s[a] === '-' &&
        s.slice(a + 1, a + 1 + b).match(/^[0-9]+$/)) {

        ans = 'Yes'
    }

    console.log(ans)
}

main(require("fs").readFileSync("/dev/stdin", "utf8"));