const fs = require('fs')\nconst stdin: string = (process.platform === 'linux'\n ? fs.readFileSync('/dev/stdin').toString()\n : `4 4 3\n0111\n1111\n1111\n1110`\n).split('\\n')\n\nconst input = (() => {\n let line = 0\n return () => stdin[line++]\n})()\n\nconst [n, m, k] = input()\n .split(' ')\n .map((str) => parseInt(str))\n\nconst map = new Array(n).fill(0).map(() =>\n input()\n .split('')\n .map((str) => parseInt(str))\n)\n\nconst dx = [0, 0, 1, -1]\nconst dy = [1, -1, 0, 0]\n\nconst visited = new Array(n)\n .fill(0)\n .map(() => new Array(m).fill(0).map(() => new Array(k + 1).fill(false)))\nconst queue: { x: number; y: number; cost: number; k: number }[] = []\n\nqueue.push({ x: 0, y: 0, cost: 1, k })\n\nlet result = -1\nwhile (queue.length) {\n const { x, y, cost, k } = queue.shift()\n\n if (x === n - 1 && y === m - 1) {\n result = cost\n break\n }\n if (visited[x][y][k] === true) continue\n\n visited[x][y][k] = true\n\n for (let i = 0; i < dx.length; i++) {\n const next = { x: x + dx[i], y: y + dy[i], cost: cost + 1, k }\n if (next.x < 0 || next.x >= n || next.y < 0 || next.y >= m) continue\n // if (visited[next.x][next.y][next.k]) continue\n if (map[next.x][next.y] === 1) {\n if (k > 0) next.k -= 1\n else continue\n }\n queue.push(next)\n }\n}\n\nconsole.log(result)