Find the number of non-negative integer solutions to x1+x2+x3+x4=10x_1 + x_2 + x_3 + x_4 = 10x1+x2+x3+x4=10 such that x1≥1,x2≥2,x3≥3x_1 \geq 1, x_2 \geq 2, x_3 \geq 3x1≥1,x2≥2,x3≥3.
35
56
84
120