/*
 * Complete the 'solve' function below.
 *
 * The function is expected to return an INTEGER.
 * The function accepts following parameters:
 *  1. INTEGER n
 *  2. INTEGER m
 */
const MOD = 1E9 + 7;
function solve(n, m) {
    // define the matrix
    const memo = new Array(n+1).fill(null).map(el => new Array(m+1).fill(0));
    // first row
    for (let i=1; i<=m; i++) memo[0][i] = 1;
    // first col
    for (let i=1; i<=n; i++) memo[i][0] = 1;
    
    // now the grid
    for(let i = 1; i <= n; i++) {
        for (let j = 1; j <= m; j++) {
            memo[i][j] = (memo[i][j-1] + memo[i-1][j]) % MOD;
        }
    }
    // this is our answer
    return memo[n][m]
}