input = require('fs').readFileSync(process.stdin.fd, 'utf8')
lines = input.split('\n')
line = lines[0]
j = 1
for(i = 0; i < line.length; i++) {
    if ((i+1)%2) {
        if (line[i] == 'L') {
            j = 0
            break;
        } 
    } else {
        if (line[i] == 'R') {
            j = 0
            break;
        } 
    }
}

NY = ['No', 'Yes']
console.log(NY[j])
